TV & Video Hifi Computers What’s New!
/
E xclusive to Dick Smith
Electronics, these popular
Velleman kits are produced and
assembled in Belgium, and all come
with a re-usable plastic container,
pre-screened and pre-drilled PCBs
and all components stripped in order
of assembly.
Parking radar
No more parking problems with this
kit emitting ultrasonic soundwaves to
‘measure’ the distance between
your car and other obstacles. A
signal is generated when the pre¬
set distance is crossed.
Supply voltage: 10-15V DC/16mA.
Kojak siren
Create or imitate sirens of all
kinds by adjusting three trimmers.
Powerful sound with an additional
2W amplifier on the PCB. Power
supply: 8-14V DC.
Headlight indicator
Set this headlight indicator either
U to indicate the headlights should
( be switched off after turning off
the ignition, or to indicate that
the headlights should be switched
. on once the engine is on. Only
(5 " B D Dg'Ol three wires needed to hook up.
Supply voltage: 12V DC.
K 1304
24 !
K 1300
Sound generator
With one output for direct
Screen wiper robot
Select up to three different time
intervals (2-10-15 seconds) for the
windscreen wipers of your car. Manual
includes installation instructions for
most cars. Relays on PCB.
*y|
a mixer panel or amplifier, generate
$ 26 91
■ l
V '
i sound effects like phaser and
i and explosions.
[Supply voltage: 8-10V DC/100mA,
IW speaker output.
K 1301
PHONE FAX &
MAIL ORDERS
direct link
DiCK^SMITH
ELECTRONICS
PHONE: 1300 366 644 (Local Call Charge) FAX: (02) 9395 1155
MAIL: DICK SMITH ELECTRONICS, Direct Link Reply Paid 160.
PO Box 321, North Ryde NSW 21 13 (No Samp Required)
Please add postage (up to 5kg) to your order, as follows:
• $4.00 Up To $50 • $7.50 $51 Up To $100 • $9.00 $101 Up To $500 • $11.00 over $500
(quote available for air/road freight or if over 5kg) email: dse.directlink@bigpond.com (enquiries only)
•Major Credit Cards Accepted. • Gift Vouchers Available
LED control of set fluid level: low,
middle, high. Controller: relay
automatically switches a pump to keep
fluid level between low and high marks.
If sensor detects a level too high or low
the relay activates a bell or the alarm
device. (Not included)
K 1307
For further information, orders or the
location of your nearest store call:
1300 366 644 (Local Call Charge)
Or Fax: (02) 9395 1155
B 3443 IFC
Australia’s largest selling electronics magazine — Established in 1922
September 1998 Volume 60, No. 9 www.electronicsaustralia.com.au
World of Electronics
6 What’s New Improved digital cameras from Canon and Olympus
10 The Challis Report Pioneer’s PDP-V401E 40”plasma flat screen
14 Quality Rising, Prices Still Falling The latest digital cameras...
20 Olympus Camedia C-1400L Zoom lens, SLR viewfinder — wow!
24 Moving People Safely with Electronics - 1 Car safety technology
62 Moffat’s Madhouse Grrrrid-Lock: Can electronics help?
70 Vintage Radio Two valve sets — 1927 to the pre-octal era
74 Computer Clinic Creating your own Windows program, with the CGI
Projects and Technical
34 Serviceman The amp that was very nearly an expensive boat anchor!
42 Circuit & Design Ideas Universal IR controller for a PC; more...
44 ‘Front End’ for PC Audio Recording Use it to make your own CDs
50 $10 Wonders 15 — A ‘designer’ door alert
56 Intelligent Baby Alarm Using the Basic Stamp microcontroller
Columns and Comments
4 Letters to the Editor DVD players and regions; engine cutouts again
5 Editorial Viewpoint From playtoy to invaluable tool, in a few years!
30 Forum Atmospheric research isn’t new; and TBC or video synchroniser?
67 Information Centre MOVs, battery ratings and the Y2K issue...
Departments
33 Book Reviews
76 EA History, Crossword
82 EA Subscriptions Offer
83 Marketplace
97 Webwatch
98 Directory of Suppliers
98 Advertisers Index
98 Notes & Errata
Impressive performance
The new Olympus C-1400L has a 3X
zoom, TTL viewfinder & higher-res
images. (See our feature on p. 14 too)
Big screen, huge impact...
Pioneer s new plasma display has
great impact, as does its price (gulp!)
Audio recording ‘front end’
On the cover uciir
Volvo s S80, just
released, features
a wealth of safety
features — many
of them based on
electronics. As
well as the airbags
used in previous
models, there’s a new Inflatable Curtain
that deploys in 25ms, to provide more
side impact protection. See our feature
story on car safety starting on page 24.
(Photo courtesy Volvo Australia)
Like to try digital recording, using
your PC? This new project can help...
Professional Electronics
78 News Highlights Bluegum buys Alcatel’s Liverpool manufacturing plant
84 Solid State Update CCD and CIS signal processor from Analog Devices
86 New Products Handheld tester finds comm cable faults; tiny switcher
88 Silicon Valley Newsletter Will Apple bounce back with the new iMac?
90 Designer’s Guide to Charging Li-Ion Batteries - 2 Charger circuits
93 Spotlight on Software Leprechaun’s Macro Virus Buster
94 Computer News & New Products Handheld Fast Ethernet link tester
ELECTRONICS Australia, September 1998
3
MANAGING EDITOR
Jamieson Rowe, B.A., B.Sc., SMIREE, VK2ZLO
TECHNICAL EDITOR
Rob Evans, CET (RMIT)
PROJECT DESIGNER/WRITER
Graham Cattley
PRODUCTION EDITOR
Witold Budzynski, B.Sc.
CONTRIBUTORS
Louis Challis
Roger Johnson, VK5ZKP
Jim Lawler, MTETIA
Jon Loughron, Assoc. Dip. Elect.
Tom Moffat, VK7TM
Peter Phillips, B.Ed., Dip Ed., ECC
READER SERVICES CO-ORDINATOR
Ana Marie Zamora; phone (02) 9353 0620
DRAFTING
Jean-Baptiste Cattley
ADVERTISING MANAGER
Jon Lesjak; phone (02) 9353 0734
ADVERTISING PRODUCTION
Pamela Sceats; phone (02) 9353 0629
PRODUCTION MANAGER
Brett Baker
CIRCULATION MANAGER
Michael Prior
EDITORIAL DIRECTOR
Christine Whiston
GENERAL MANAGER
Geoff Baggett
HEAD OFFICE
PO Box 199, Alexandria 2015.
180 Bourke Road, Alexandria 2015.
Phone (02) 9353 0620; fax (02) 9353 0613
E-mail: electaus@magna.com.au
Web site: www.electronicsaustralia.com.au
Computer Bulletin Board: (02) 9353 0627
Subscriptions Enquiries:
phone (02) 9353 9992; fax (02) 9353 0967.
INTERSTATE ADVERTISING SALES
MELBOURNE: Kayren Browne
Level 8. 492 St Kilda Road, Melbourne 3004.
Phone (03) 9864 1222; fax (03) 9864 1211.
BRISBANE: Graham Smith
26 Chermside Street, Newstead 4006.
Phone (07) 3854 1119; fax (07) 3252 3692.
ADELAIDE: Sue Bowshall
98 Jervois Street, Torrensville, 5031.
Phone (08) 8352 7937; fax (08) 8352 6033.
PERTH: JWP Media Specialists
64 Francis Street, Karrinyup 6018.
Phone (08) 9446 2792; fax (08) 9446 2740.
ELECTRONICS AUSTRALIA is published by FPC
Magazines, a division of Eastern Suburbs
Newspapers Partnership, which is owned by
General Newspapers Pty Ltd.
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Double Bay Newspapers Pty Ltd.
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Brehmer Fairfax Pty Ltd.
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180 Bourke Road, Alexandria, NSW 2015.
Copyright © 1998 by FPC Magazines, Sydney. All
rights reserved. No part of this publication may be
reproduced in any way without written permission
from the General Manager or Managing Editor.
Printed by Macquarie Print, 51 - 59 Wheelers
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Distributed by Newsagents Direct Distribution
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ISSN 1328-6218
* Recommended & maximum
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M'NIII
abc
Letters fo
Stick with leeches?
Being but a humble technician, I’ve
always entrusted my health to my GP.
However as a result of reading your
recent Forum series I now realise that my
erythrocites are being invaded by alien
viruses.
Since your research has obviously
provided you with considerable expertise
on the topic, I am really desperate for
your advice. Do you reckon that I ought
purchase Dr Beck’s Blood Cleaner, or
should I just stick with the leeches? ;-(
John Harvey, Clermont Old.
Engine cutout legality
A letter in the July edition refers to an
engine cutout caused by a broken fan
belt as being illegal.
I don’t think so. LPG convertors will
freeze up in seconds (stopping fuel
supply) if the fan belt breaks — and they
are legal.
Andrew Caris (via e-mail)
Idea not new
Graham Pratt’s idea about using resist
ink to print circuit boards directly from a
CAD program isn’t new (EA July 98).
About 10 years ago I was making one-
off boards for research using resist ink in
a pen plotter and plotting directly onto
the copper surface. The resist ink
happens to be the same as the ink used
by farmers to write numbers on the ear-
tags of cattle, and you can buy it cheaply
in 200ml bottles (which makes more
circuit boards than you will ever need).
The trouble with inkjet printers may be
that they are much more particular about
the flow qualities of the ink than a plotter
pen.
Chris Henderson (via e-mail)
Aristocrat radio
I am rejuvenating a seven valve Aristocrat
ESM radio (1930 vintage), and wonder if
any of your readers have a circuit dia¬
gram or any servicing details (IFT fre¬
quencies, etc).
The circuit is a superhet with a triple
gang tuning capacitor linking a 6K7G RF
stage in front of a 6A8G heptode
frequency changer, followed by an
(unreadable) IF stage, a 6B6G
demodulator and 6V6G output with a
5Y3 HT rectifier and 6G5 magic eye
the Editor
tuning indicator. Apart from the RF stage,
the circuit appears broadly similar to that
of the RCNZ radio in your magazine issue
of September 1994.
The set is powered by a (nominally)
380-0-380V transformer with full wave
rectification. 320V DC on the cathode of
the 5Y3 rectifier falls to 140V after
smoothing by the 2800£2 field coil of the
speaker (indicating a reasonable
consumption of about 60mA). This
voltage is well below the 250V
anticipated for the valves, but after the
mandatory replacement of paper
capacitors, the radio is surprisingly
receiving speech and music without
distortion.
For your information, I’m a chemical
engineer who cut his teeth on home-built
TV’s using war surplus ex-RAF 1355
receivers and VCR517 tubes in Britain in
the early 1950s. The heating from the
multitude of VR65’s served a dual
purpose of keeping the room warm in
winter! The inevitable conversion to
transistors and ICs through building
circuits in Electronics Australia over 25
years has not diminished my interest in
your articles on thermionic valves.
J.M. Costello, Woronora NSW.
DVD players
Having read your review of the Philips
DVD840, I thought I should write. I have
been following the development of DVD
since the beginning, always knowing that
I wanted to buy a player. However, that
was put on hold when I read that there
would be zones to stop individuals
importing, pirating, etc movie titles.
Thankfully the Internet came to the
rescue, with many sites describing how to
defeat the zone coding in each brand and
model of player. Armed with this
information, and on a recent holiday in
Malaysia, I bought a DVD player (for
considerably less than in Australia —
$600 US!). Imagine my amazement
when told that my purchase had been
already modified by the distributor in
Malaysia so as to defeat zoning! To prove
it, the vendor played me a disc stamped
Zone 1, and another Zone 4.
Recently, in an American magazine, it
was proudly reported that sales of DVD
players and software had overtaken VHS
for the first time. With the advent of the
Editorial Viewpoint
‘Net, and shopping on-line, it’s not hard
to understand why.
Frustrated Australian consumers would
be very tempted to buy a DVD player
coded for Zone 1 (US and Canada),
purely because it guarantees the
individual access to more than 2500
movie titles, and interactive games,
available now. By contrast, I have been
able to source fewer than 20 titles in
Australia, with explanations from retailers
that “the Copyright holder won’t allow
that title into Australia”. Stargate and The
Fifth Element are two such examples.
Why? What do the copyright holders
have to gain? Are they waiting for people
to stampede the distributors looking for
titles? A typical ‘chicken and egg’
situation, I think! They won’t release the
titles until everyone has a player, but
people won’t buy the players until there’s
a good range of movies! In the age of the
Internet, the Australian distributors of
movies are being foolishly parochial.
It is my humble opinion that DVD will
fail in Australia, like DCC and MiniDisc.
There WILL, however, be booming import
activity, with many people opting to buy
with their Internet browsers and credit
cards. Surf to www.lasersedge.com,
and you’ll see why. The prices, and the
range!
Mark Borchers, Melbourne Vic.
It may have worked
Regarding the circuit shown in Fig.4 of
July’s Vintage Radio, on page 50, surely
the circuit will vtfork as the A- supply for
filaments is not earthed, whereas the
bottom of the RF coil IS earthed.
Therefore the secondary of coil 5 is not
shorted out. It will pump the filament up
and down with the audio, whilst holding
the grid at earth potential.
It looks as if all filaments and B supply
follow audio with respect to earth and the
bottom of the RF coil, if you get my
meaning!
Weird, but it probably did work.
Peter Ball (via e-mail) ❖
Letters published in this column express the opinions of
the correspondents concerned, and do not necessarily
reflect the opinions or policies of the staff or publisher of
Electronics Australia. We welcome contributions to this
column, but reserve the right to edit letters which are very
long or potentially defamatory.
i
From playtoy
to invaluable
resource
in only a
few years...
tool,
only
he other day I found myself doing two superficially
quite different things, in short order. One was using the
World Wide Web or ‘WWW’ to get some information on
a new medication that my wife had been prescribed, by a
doctor too busy to answer her questions about it; the other
was looking up an article in an old issue of the magazine
itself. I was really impressed by the contrast between the
two actions, and in particular what they revealed about the
dramatic developments that have taken place in computers
and information technology, in the last few years.
It turned out that I was able to get some really good infor¬
mation on the medication concerned,
from both the manufacturer’s web site
and also from a consumer information site
in the US. There was a full pharmacologi¬
cal rundown, information on how it’s
believed to work, indications and contra¬
indications, recommended dosage levels
and so on — plus a great deal of informa¬
tion on the research and testing that had
gone on in various countries, before it had
been approved by bodies like the
American FDA.
All of this information was available
freely and in very short order, simply by
making use of the tremendous resources
provided by today’s Internet/WWW, its
search engines and the databases available at web sites around the world. Just as
you can also get excellent up-to-date information on almost any electronic device or
component — often faster than looking up a data book.
We tend to take these resources for granted now, don’t we? But when I was look¬
ing up something in the May 1997 issue, I noticed a couple of articles which remind¬
ed me just how far we’ve come in the last 21-odd years...
Back then, we were building and struggling to understand the first generation of DIY
microcomputers and ‘evaluation kits’, like the Mini Scamp and the Motorola 6800 kit.
Even the first true 8-bit personal computers like the Apple II and the Tandy TRS-80
were yet to be released, and many people in electronics thought we were foolish to
even bother with ‘those little toy computers’ — they’d never be of much use!
Little did we even dream of the kind of computing resources that many of us would
have on our desktops today — Pentium and Pentium II powered beasts screaming
along at 200MHz-plus speeds, with tens of megs of RAM, multi-gigabyte hard disks
and high-speed modems, and running all kinds of powerful software.
The same kind of developments have taken place with the internet, of course.
Initially it was of interest only to scientists, academics and the military, to link up their
big computers and networks. Then it began to be used for international e-mail, and
other people started to get involved. Then the WWW appeared and began to blossom,
and both the resources and users began to grow exponentially.
Only three or four years ago, I confess that I myself tended to see the WWW as a
huge electronic information ‘rubbish dump’, with a small amount of fact buried almost
irretrievably in an enormous amount of uninformed opinion. As with DIY computers 20
years ago, it seemed little more than a hi-tech time waster. But that’s all changed,
thanks to the development of primary and meta ‘search engines’, and the enormous
amount of genuine information that’s been made available.
Things can move pretty quickly from the ‘toy’ stage to the ‘invaluable resource tool’
stage, can’t they?
Jim Rowe
ELECTRONICS Australia, September 1998 5
>UT
in the ever-changing world of electronics
Hi-res multimedia video projector
Hitachi’s new CP-X950 is a true XGA resolution (1024 x 768) LCD
panel based multimedia projector, claimed to be ideal for business and
educational applications where high resolution is essential, such as in
the display of fine CAD drawings or high resolution photo images.
A three-panel LCD projector, it uses a Hitachi ‘Polarisation
Converter’ to provides 550 ANSI lumens of light output — one of the
brightest displays in its price class. And despite having a weight of
only 9kg, it’s enclosed in a solid frame that needs no extra mounting
brackets if ceiling mounting is desired. The rugged frame also protects
the unit from transit damage and distortion. For further protection the
zoom lens is fully mounted within the projector case and a built-in lens
shutter protects the lens from accidental scratching or worse.
The CP-X950 incorporates a Multi-Scan Panel that accepts two
PC inputs, two S-Video and two composite video inputs. These are
all automatically detected and the display resolution adjusted
Sharp Handheld PC features Windows CE 2.0
Sharp Corporation says its new pocket-sized Handheld PC with
Windows CE 2.0 is capable of giving a complete multimedia pre¬
sentation. It features either a mono or a full colour screen, reflecting
Sharp’s dominance in LCD screens — they claim to produce 60% of
those currently sold worldwide. Surprisingly there’s also a VGA
output, which allows the HPC to facilitate big-screen presentations.
Other features of the HC4100 A include an IrDA infra-red port for wire¬
less exchange of data, SMB of memory and an easy-touch keyboard. An
optional extra is a digital camera which slips into the unit’s PC card slot.
RRP for the HC4100A with mono colour screen is $999, or with
colour screen $1499. The optional digital camera is $599. For more
information circle 140 on the reader service card or contact Sharp
Corporation, 1 Huntingwood Drive, Huntingwood 2148.
depending on the signal frequency from compressed S-VGA, true
XGA and expanded VGA and S-VGA.
Available from authorised Hitachi dealers Australia wide, the
CP-X950 has an RRP of $13,499 including tax. For more informa¬
tion circle 145 on the reader service card or contact Hitachi
Australia, 13-15 Lyonpark Road, North Ryde 2113.
New palm-size PC
has voice control
Casio’s new Cassiopeia E-10 is
claimed as one of the first palm size
PCs powered by Microsoft Windows
CE 2.0 to go on sale in Australia, and
is claimed to deliver instant access to
vital business and personal informa¬
tion whenever and wherever it is need¬
ed — plus voice control.
Compact, lightweight and easy
to use, it offers users ‘seamless
desktop synchronisation’, infrared
(IR) capabilities, 4MB of RAM
and 8MB of ROM memory,
expandability via its CompactFlash
port and a large easy to read 240 x
320 dot LCD screen. Backlighting
provides easy viewing of data even in
the dark, while a pop-up handwriting
or keyboard panel and taskbar allows
up to 30% more viewable screen.
Applications can be launched either
by pressing one of the four application
buttons, or by voice command using
bundled software. Data input and other
operations are performed by using a sty¬
lus or pressing the on-screen keyboard.
Side positioned scrolling, enter and
escape buttons make it possible to oper¬
ate the E-10 with one hand.
The Cassiopeia E-10 has an RRP of
$699 and is available at leading
resellers and retail stores. For more
information circle 149 on the reader
service card or contact Mobex, 72-74
Gibbes Street, Chatswood 2067.
6
ELECTRONICS Australia, September 1998
W]
High-end CDP/tuner for mobile hifi
Not intended for the average car audio lis¬
tener, Pioneer’s new DEX-P88R compo¬
nent tuner is designed for the audio enthusi¬
ast who is not satisfied with a factory-con-
figured system. It is claimed to employ the
very latest in car audio features, including
‘Sound Q’ — a combination of four tech¬
nologies: Hi-Bit Digital Processing, Legato
Link Conversion, Hi-Volt Preamp Outputs,
and Zero-Bit Muting.
Hi-Bit Digital Processing apparently com¬
bines the best features of both single-bit and 20-
bit conversion. It uses a single-bit DAC, but
first converts each 16-bit digital ‘word’ into a
new 20-bit word, for enhanced detail. Pioneer’s
Legato Link circuit then restores the upper har¬
monics of the music, normally lost during the
digital recording process.
The preamp outputs have been
enhanced by the newly reworked Hi-Volt
(4V) design to provide a clean¬
er and more powerful signal to
the system’s amplifiers.
The DEX-P88R will connect
to a multiplay CD changer that
can be mounted out of sight in
the boot, under a seat, or even
in the glove box. It also features Pioneer’s
Supertuner III Qiiartz-PLL electronic
tuner, claimed to offer greater sensitivity,
exceptional handling of multi-path inter¬
ference, and increased resistance to signal
intermodulation.
The DEX-P88R has an RRP of
$999 and is available at Pioneer
dealers throughout Australia. For
more information circle 144 on the reader
service card or contact Pioneer Electronics
Australia, 178-184 Boundary Road,
Braeside 3195.
Improved digital camera from Canon
Canon’s new PowerShot A5 digital camera is
stylish and pocket-sized, offering high resolu¬
tion images with a low distortion lens, capa¬
bilities for high speed capture and storage of
images, and a range of memory options.
The PowerShot A5 features a fast 5mm
f/2.5 lens that focuses accurately and quick¬
ly regardless of lighting conditions. Shutter
speeds are from 1/6 to 1/750 second and
users have a focusing range from 0.5m -
infinity or 90 - 500mm in macro mode. An
810,000 pixel CCD sensor captures the
images at optimum resolution, and a dedi¬
cated IC then ensures high speed image sig¬
nal processing so that the image is quickly
stored whilst maintaining maximum quality.
Users can select any one of five resolution
modes (up to 1024 x 768) to allow optimum
balance of resolution and stored image
capacity. The camera comes with an 8MB
CompactFlash card as standard, holding
between 44 - 89 images in fine mode or 125
- 236 images in normal mode (dependent on
JPEG compression). Additional Canon
CompactFlash memory cards are available
from 2MB- 15MB.
The PowerShot A5 comes with both an
LCD viewing screen and an optical
viewfinder. The low temperature polycrys¬
talline silicon TFT used in the LCD screen
ensures exceptionally sharp and bright
images, even outdoors.
The camera comes with a range of fully
integrated software to extend its imaging
capabilities. It measures just 103mm x
68mm x 32.5mm, weighs approximately
230g without batteries and has an RRP of
$1299. For more information circle 143 on
the reader service card or contact Canon
Australia, 1 Thomas Holt Drive, North
Ryde 2113
Open-panel hifi speaker is
made in Australia
The latest version of Lorpen Audio’s HP3
open panel hifi speaker (due out next
month) features improved production tech¬
niques, revised panel shape, new drivers and
more elegant styling. This results in a better
looking and sounding speaker while main¬
taining the attractive pricing.
The HP3 design features four 170mm dri¬
vers mounted on a panel of machined 50mm
customboard. This open panel handles the
upper bass, midrange and lower high fre¬
quencies. The dispersion pattern of sound
from the panel is described by Lorpen
Audio as an enhanced dipole radiating pat¬
tern — similar to other panel speakers, but
with better horizontal dispersion.
Bass frequencies are handled by an inbuilt
subwoofer system at the bottom of the panel,
featuring a 210mm bass driver. High fre¬
quencies are handled by a dome tweeter
mounted in the middle of the panel itself.
This novel design produces a very differ¬
ent sound from conventional box designs.
The HP3s are claimed to have a smooth
non-fatiguing sound quality, even at loud
volume levels, and to be able to resolve sub¬
tle low level detail. Stereo imaging is
claimed to be excellent. The high efficiency
(quoted at 90.5dB) means amplification
(both valve and transistor designs) can be
chosen for their overall sound quality, not
just the power output specification.
The RRP for the new Lorpen Audio HP3
system is $2945.00. For more information
circle 147 on the reader service card or con¬
tact Lorpen Audio, 11 Moldavia Walk,
Osborne 5017.
ELECTRONICS Australia, September 1998
7
A
WHArS IfVff the ever-changing world of electronics
SuperDisk goes USB
Imation Corp has released an external USB
version of its 120MB SuperDisk drive,
developed in conjunction with
Panasonic and announced at
the recent Mac World
Expo in New York. It
was developed
specifically to mate
with Apple
Computer’s new
iMac computer, and
Mac-formatted
SuperDisks will be made
available to suit it. The drive is
also compatible with both 720KB and
1.44MB floppy disks. RRP in the US is
around US$189.
‘Third generation’ Olympus digital camera
Olympus have announced the latest addi¬
tion to their award-winning range of
Camedia digital cameras, the C-840L. This
provides a resolution of 1.3 million pixels
(1280 x 960) and includes many new fea¬
tures, whilst retaining the popular features
of the C-820L (which remains in the
range), including its compact lightweight
ergonomic design,
PAL video out and
SmartMedia card
usage.
Exceptional
image quality is
achieved by a high
quality 5.5mm all¬
glass aspherical
f/2.8 autofocus
lens, low data
compression
ratios, and a host
of other sophisti¬
cated Olympus
technologies. In
addition to a PAL
video output for
easy viewing of
shots on a TV, and
the built-in colour LCD, users also have
the option of creating prints directly from
the camera with the Olympus P-300E
dye-sublimation printer via its direct con¬
nect capabilities.
Three resolution modes are provided
(Standard Quality at 640 x 480, High
Quality at 1280 x 960, and Super High
Quality 1280 x 960 with least image com¬
pression for superior image quality).
Exposure control allows users to override
the automatic exposure system +/-1 step
for lighting compensation, and a sophisti¬
cated multi mode flash offers auto, red eye
reduction, fill flash, and flash off settings
to accommodate a variety of lighting con¬
ditions.
Files are saved in an industry standard
format (JPEG) that virtually any image
editor, word processor or desktop pub¬
lishing application can use and recognise.
With the addition of an optional PCMCIA
or floppy disk adapter, images can also be
downloaded without needing cables.
Slim 14” LCD monitor
Panasonic has released the new ‘Panaflat
LC40’ 35.6cm (14”) LCD computer
monitor, boasting colour reproduction
and resolution comparable to CRT moni¬
tors but with a depth of only 62mm —
making it well suited for crowded desks.
The Panaflat LC40 can be used like a
conventional monitor and has no special
hardware or software requirements. It
has an analog interface that plugs into
any personal computer’s RGB connec¬
tor. A 15 pin D-sub connector with
adapters for Macintosh personal com¬
puters ensures compatibility with most
computer hardware.
An automatic pixel converter guaran¬
tees uniform thickness in both horizon¬
tal and vertical lines and natural screen
appearance at all resolutions. This
marks a major improvement over previ¬
ous LCD monitors, which could not
display 640- or 800-dot signals accu¬
rately at full-screen size. All signal res-
Macro focussing has also been
improved, with the ability to focus as close
as 10cm. There’s also a 2X digital mode
for closeups in stan¬
dard resolution.
The Olympus C-
840L uses 3.3 volt
SmartMedia
removable media.
A 4MB card is
included with the
camera, but addi¬
tional 2MB, 4MB,
and 8MB cards can
be used so there is
no restriction on the
number of photos
that can be cap¬
tured.
Designed with the
consumer in mind,
the camera is light¬
weight at 245g, and
very compact with dimensions of 128 x 65
x 45mm. It has a large 51mm smudge-resis¬
tant LCD screen and carried an RRP of
approximately $1499.
For more information circle 146 on the
reader service card or contact R. Gunz
(Photographic), Locked Bag 690,
Beaconsfield 2014.
8
ELECTRONICS Australia, September 1998
olutions smaller than 1024 x 768 are
converted to display at full-screen
dimensions, ensuring full use of avail¬
able screen space.
The screen of the LC40 can tilt up to 30°
for improved visibility, and a keyboard can
rest on the screen’s stand to conserve desk
space. A cable cover is provided to hide
connections at the rear. The LC40 displays
16 million colours with a minimum bright¬
ness of 150cd/m : , and an anti-glare coating
prevents reflections and dust build-up.
Power consumption is only 45W.
The Panaflat LC40 is available from
specialist outlets for an RRP of $5650.
For more information circle 148 on the
reader service card or contact Panasonic’s
Customer Care Centre on 132 600.
Ericsson’s ‘Mobile
Communication Solution’
Ericsson Australia has launched its MC 16
handheld computer, said to provide a one-
stop, out-of-the-box mobile communica¬
tion solution. It allows the user to send and
receive e-mail. Short Message Service
(SMS) and faxes, while also enabling
access to the internet and intranets.
The MC 16 comes with the DI 27
infrared modem, which clips onto the base
connector of any Ericsson 600 or 700 series
mobile phone, linking the phone and MC
16 without cables. The DI 27 is extremely
small, weighing less than 10 grams and,
unlike traditional PC card modems, doesn’t
drain power from the computer.
The MC 16 uses Windows CE 2.0 as the
operating system, which includes an Inbox
application. My Ericsson Phone software
and Ericsson Mobile internet. It weighs just
442g with batteries and uses a fast RISC
60MHz processor with 8MB RAM and
10MB ROM.
For more information circle 141 on the
reader service card or contact Ericsson
Australia.
3.8kW motorised
‘ghetto blaster’
Pioneer Electronics says its showpiece
‘Muscle Truck’ represents the ultimate in
car audio innovation, and is set to ‘turn
heads’ at selected Australian car audio
and motor/lifestype shows over the next
two years.
Essentially the Muscle Truck is a cus¬
tomised 1996 American GMC SLE Crew
Cab, fitted out with proprietary voice
recognition technology, anti-theft mecha¬
nisms, dual video display screens and a
slew of amplifiers and speakers produc¬
ing enough power output to fill the
Melbourne Cricket Ground.
The heart of the sound source is five
GM-X922 and two GM-X904 class A, four
channel amplifiers capable of producing
power levels up to 3800 watts. To supply
the current needed to drive this arsenal is a
bank of heavy duty, heavy current Gel-Cel
70 batteries and IF capacitors, fitted in a
removable tray seated between two-banks
of 10 x 12” TSW-1200C subwoofers (20 in
total) — giving the vehicle ‘more punch
than Mike Tyson’.
Additional speakers include a range of
mid-range, mid sub and tweeter units.
Front end components include Pioneer’s
CDX-P5000 50-disc Stacker, CD-VC50
Voice Control Unit and DEX-P88R Multi-
CD controller/tuner. Total value of the
audio components alone exceed $30,000.
Not much room for the family or taking
the rubbish to the tip, but a great way of
showing off Pioneer’s mobile audio gear... ❖
ON LINE
ELECTRONICS
Modules:
Electrical Principles 1
60 hrs $150
Electrical Principles 2
60 hrs $150
Analogue Systems
40 hrs $100
Feedback, Filters & Oscillators
40 hrs $100
Amplifiers 2
40 hrs $100
Circuit Analysis 1
60 hrs $150
For further information contact Jim
Mark * (03) 5434 1430 or
email: hmark@britafe.vic.edu.au
BENDIGO REGIONAL
INSTITUTE OF TAFE
The only training and education provider in
Central Victoria with ISO9001 Quality
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TAP INTO OUR
RESOURCES
The Industrial Affiliates program at
Griffith University, invites industries to
offer work to final year Microelectronic
Engineering students for a period of
three months. The students work with
industries, producing research and
design solutions from concept to
prototype. In the past six years, 200
Griffith students have worked on
industry projects from the conceptual
stage through to completion of
prototypes. Industry projects are now
being accepted for the next program.
To tap into these resources,
contact Carol-joy Patrick on telephone:
(07) 3875 5007, fax: (07) 3875 6726
or email: cj.patrick@sct.gu.edu.au
GRIFFITH UNIVERSITY
LBC&M GU80608
ELECTRONICS Australia, September 1998
9
READER INFO NO.3 READER INFO NO.2
Video & Audio
The Challis Report
Pioneer's PDP-V401E
Full Colour Plasma Display
This month, hard on the heels of his review of Pioneer’s under-$1000 DVD player, our
intrepid reviewer Louis Challis had the chance to evaluate the first of their new gee-whiz
plasma flat-screen displays to reach these shores. And its performance just about blew
him away. There’s just one problem: how can he — and most of us, for that matter —
contain our frustration until the price of these beasts comes down to a level where we
might be able to afford one?
I f you read my report on the Pioneer
DV505 DVD player last month, you may
well recall the degree to which the NEC
PlasmaSync 4200W plasma display
impressed me. Not only was I excited by the
latest complementary advances in video tech¬
nology, but more significantly 1 extolled its
virtues. Indeed, I was sufficiently impressed
that I imparted my feelings to the sales team
at Pioneer Australia. 1 rather brashly suggest¬
ed that as soon as they received
their first plasma display, I would
welcome the chance to review it!
Needless to say, I had expected
some weeks or even months to
elapse before they’d take me up
on this offer. However it all hap¬
pened much sooner. In fact it was
only a week later that Pioneer
expedited the delivery of the very
first PDP-V401E into the country,
straight to my office...
What could I do? I couldn’t lose
face and not review it, particularly as
they supplemented that delivery with
the first unit of their brand new (groundbreak¬
ing) DVL-909 combination (or ‘combo’) play¬
er, to assist me in conducting my review. The
DVL-909 happens to be the first, and possibly
the only, DVD player in the world which simul¬
taneously provides its owner(s) with the ability
to play Region-4 DVD’s, PAL and NTSC
laserdiscs, conventional CDs, the next genera¬
tion of high resolution CDs, and Video CDs.
But back to the plasma screen. Pioneer’s
PDP-V401E has an immediate and pragmatic
attraction in that, unlike the NEC PlasmaSync
4200W, which has been optimally configured
for a 16x9 widescreen format display, the
PDP-V401E has been sensibly designed to
satisfy the more common conventional 4x3
format — which is the basis for the majority
of current Australian and other international
TV transmissions. The 4x3 format is also that
still preferred for the majority of computer
and related video displays.
The PDP-V401E’s designers have focused
their initial product in satisfying the demand¬
ing requirements of the lucrative commercial
market for large displays. That market craves
for a display system with minimal depth,
maximum brightness and one that can simul¬
taneously, or more specifically sequentially,
fulfil the diverse requirements of commercial
transportation, educational and residential
A diagram available on Pioneer’s web
site, giving an idea of the cell
construction used in its PDP-V401E
plasma screen.
requirements and applications.
The more critical commercial applications
generally impose an added requirement
involving the ability to display a computer
screen’s output in a normally illuminated
room. That requirement prejudices the
majority of conventional projection TV’s
and more significantly virtually all rear-pro¬
jection TV sets, which only really function
adequately in an environment with relatively
low level illumination.
Pioneer claims to have gone one step fur¬
ther than other plasma display manufactur¬
ers. They claim to have achieved the high¬
est brightness level in the world, with an
output illumination level of 400cd/nf. That
illumination is achieved through the adop¬
tion of what they describe as being an ‘opti¬
mum cell structure technology’.
Pioneer also claims to have achieved a
high, if not the highest, contrast ratio current¬
ly available (150:1), to ensure brilliant colour
contrast. This is achieved by the adoption of a
special square plasma cell structure, in which
each of the complicated individual parallel
cell structures is incorporated in minuscule
1.26 x 1.26mm repetitive modules.
Each individual plasma cell in
the screen functions on the basis of
the application of electric charges
to the electrodes on each side of the
cellular structure. The charge (or
should I say the discharge) between
the electrodes in each module then
reacts with the rare gas contained
within the gap to produce an ultra¬
violet radiation. It is this radiation
of energy which energises the
phosphors on the screen, to create
the visible light which you observe.
The light from each sub-module
combines with the light emitted from adja¬
cent pixels to produce the visual images.
Excellent resolution
Each PDP-V401E has a complement of
281,000 individual plasma cells, to gener¬
ate a picture with excellent resolution, and
with what appears to be the largest current
4x3 plasma display picture size currently
available. Although the PDP-V401E is
50mm narrower than the width of the NEC
PlasmaSync 4200W’s screen, its picture is
higher, and thus provides an outstanding
visual display with conventional 4x3 format
TV, video and computer based software.
The PDP-V401E provides a grey scale with
256 increments and an amazing 16.7 million
possible colours. I’ll have to take their word
for that, as I currently lack the ability to put
that specific claim to the test. Fortuitously
Phosphor (R)
Phosphor (G)
Phosphor (B)
Dialortrk Layer
Ooto eledrodo
Bock plate
10
ELECTRONICS Australia, September 1998
there are a large number of objective tests that
I am equipped to perform. Accordingly, I
availed myself of the appropriate hardware
and software based procedures to put the
PDP-V401E through its paces.
One of the PDP-V401 E’s nicest features is
its extremely slim profile. With an overall
thickness of only 100mm, and its adoption of
a series of five miniature cooling fans along
the right hand side of the rear panel (when
viewed from behind), it can be placed up
close to a rear or supporting wall without
significant inhibition.
With a sound reflective rear wall behind,
the resulting noise level at a distance of 2m
from the face of the display is only 36dB(A).
That sound level, although audible in the
absence of audible program material is suffi¬
ciently low to ensure that you are all but
oblivious to the presence of the fans, until
you walk up to the display unit and thereby
detect their presence.
The PDP-V401E incorporates multiple
inputs, which are located in a line along the
lower rear edge of the unit’s perimeter fram¬
ing. These provide direct connection for vir¬
tually all forms of conventional video signal
(NTSC, PAL and SEC AM), as well as SVGA
or Mac computer graphics inputs. The unit
also incorporates an RS-232 port, through
which you can exercise computer control of
the images.
I examined the display’s output when fed
with video signal from a Power Mac
9500/120, and the latest generation of SVGA
inputs from a 225MEIz Pentium II computer.
With both of those formats I was able to pro¬
duce truly superlative displays.
Field trials...
The Pioneer PDP-V401E and Pioneer DVL-
909 combo player arrived just in time for the
weekend. Fortuitously Columbia Tristar
Pictures responded to a long standing request
to provide me with a copy of MatilJa , the first
of their G classification DVDs suitable for
young children’s viewing. As it happens, that
was also the weekend on which my grand¬
children were sleeping over. I thus had the
perfect opportunity to field trial the system.
My grandchildren’s response was truly
ecstatic, and both the big-screen hardware
and the exciting software were an immediate
hit. When I finally managed to drag them
away from the PDP-V401E, the first ques¬
tion they asked was “When’s daddy going to
get a TV like this?' (That’s the one question
to which 1 delicately avoided a response!)
The PDP-V401E’s brightness level was so
high that we were able to watch the video
with all of my living room’s full complement
of lights and supplementary reading lights
switched on. The most exciting aspects of
that evening’s foray into this new video tech¬
nology were the PDP-V401E’s brightness
levels, its outstanding colour balance and its
visual ambience, all of which were as close to
being optimum as I could have hoped for.
Needless to say, my grandchildren were just
as excited as I was. But more significantly, it
was obvious that the larger screen size, and its
realistic visual impact, created a degree of real¬
ism that eclipsed anything they had ever expe¬
rienced when watching a conventional TV set,
or even when viewing a cinema screen.
It was only later, following the children’s
departure to their respective beds that 1 was
able to sit down and experiment with the
plasma display’s user controllable settings,
using the PDP-V401E’s remote control...
Actually I only discovered that there was a
remote control when I picked up the hand¬
book and noticed it listed — which led me to
look for it in its carton. I then discovered that
the unit’s default settings conformed to the
settings that I would have chosen had I
selected them myself.
During the objective testing that followed,
I was unable to fault the quality of the PDP-
V401 E’s display linearity nor its colour real¬
ism. It was only when I sat within 3m of the
screen that I was able to observe the pres¬
ence of individual pixels. There are 281,000
of those, and I had to look carefully before I
was able to identify them with still pictures.
The next morning my grandchildren plead-
ELECTRONICS Australia, September 1998
11
READER INFO NO.4
DESIGN
BREAKTHROUGH
The new VAF DC-X is a genuine
design breakthrough!
NEW LEVELS OF ACCURACY THROUGH
PHYSICAL FILTERING TECHNOLOGY:
High Sensitivity: Over 95 db/W/M
Flat Response: 35Hz-20KHz+/-2db
Deep Bass: -3db at 31 Hz
Flat Phase: 120Hz-20Khz+/-5deg
High Power: Amps up to 200W / ch
Price: $1099 Kits without cabinets
$1399 Kits with assembled cabinets
$1799 Fully assembled
13 VAF Kits Priced from $263 pr. to $8000 pr.
Custom finishes available.
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the evidence, we'd have to say VAPs 1-66 design
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For more information
FREECALL 1800 818 882
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Phone: 08 8 269 4446 Fax: 08 8 269 4460
__ e-mail: vaf@vaf.com.au _
The Challls Report
ed for yet another DVD, so we briefly viewed
half of a ‘G rated’ NTSC-format DVD on a
Region 1 (US) DVD Player. With only 525
vertical lines of resolution, NTSC DVD’s pro¬
vide an inferior picture when compared to the
625 line PAL-based Region 4 software that we
had viewed the previous evening.
Following my grandchildren’s departure, 1
was able to devote further time and attention
to assessing other parameters that would have
been of little interest to a child. Some of those
parameters will be of significant interest to
some readers, and were evaluated as a result
of questions which were initiated by other
recently completed reviews. I used both DVD
and laser disc based test software to derive the
following information:
1. Vertical and horizontal linearity: These
proved to be as close to perfection as one
could ever desire.
2. Colour smear: This is clearly visible with
laserdisc software, but much less evident
and almost invisible using NTSC-format
DVD test software.
3. Uniformity of grey scale display: This is
very good with laserdisc software and quite
outstanding with DVD test software.
4. ‘Multi-burst’ linearity: This exceeds
4MHz with laserdisc software and appears to
achieve a marginally higher figure with
DVD test software.
5. Contrast ratio between maximum white
and maximum black: This is excellent with
laserdisc software and again superior with
DVD test software.
6. Cooling fan noise emission at various
points in the viewing region in front of the
display: Virtually inaudible in the zone on
the right hand side of the screen, just audible
in front of the screen, and readily audible in
the zone to the left hand side of the screen —
measured level of 36dB(A).
7. Angular range of viewing: This exceeded
145° in the room in which we were viewing the
PDP-V401E. Note that the manufacturer claims
160° horizontal and vertical viewing angles.
In summary
Pioneer were kind enough to leave the PDP-
V401E and the DVL-909 with me for 10
pleasant days of viewing. During that period,
I was able to confirm, and indeed simply
cannot deny that the PDP-V401E viewing
quality and sense of realism eclipses that of
any conventional TV monitor screen, projec¬
tion TV monitor display, or rear projection
TV display that I have yet seen.
The PDP-V401E’s plasma display has the
ability to uplift and upstage your current per¬
ceptions of what you desire for your home
cinema or your general (or private) TV view¬
ing. As you will undoubtedly discover when
you finally get the opportunity to view one,
plasma displays like the PDP-V401E simply
set a new standard, and become the bench¬
mark against which we will now assess
video quality. ♦>
Pioneer PDP-V401E Full Colour Plasma Display
A multiformat plasma-based display screen for both video (PAL/NTSC) and computer graphics
(SVGA/MAc). Measures 946 x 740 x 100mm, weighs 30kg (unpacked), displays in 4:3 format.
Good points: Excellent image resolution (281,000 pixels), very high brightness (400cd/m 2 )
and contrast ratio (150:1), wide viewing angle (160°).
Bad points: Low level noise emission from cooling fans. For many of us, price will be the only
drawback.
RRP: About $17,000.
Available: Pioneer dealers, or contact Pioneer Electronics Australia, 178-184 Boundary Road,
Braeside 3195.
At last!
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by Peter Phillips
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order from EA Reader Services (PO Box 199, Alexandria
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12
ELECTRONICS Australia, September 1998
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READER INFO NO.6
Expanding Possibilities
Digital Cameras
Update
Quality
Prices Still
Digital still cameras are now
getting quite serious in the
consumer market. Their picture
quality continues to rise, while
prices are descending and sales
are rising. While the bulk of
happy snappers are yet to swing
over, and film technology still
has the edge in terms of
performance/price, more and
more enthusiasts are
succumbing to the lure of
instant ‘megapixel’ imaging.
by Barrie Smith
A re digital cameras a serious competitor
to traditional silver halide film cam¬
eras? Not by a long chalk — yet.
Incredibly, you can still buy a $5 plastic,
fixed focus kiddie’s camera, drop a roll of
film in and get better 10x15cm prints —
judged by serious, critical standards — than
most digital cameras on the market below
$ 2000 .
So, for the short term — say two or three
years — it looks as though digi cams will not
so much sit side-by-side or replace the tradi¬
tional cams, but establish a market sector all
their own.
Current market leaders are those from
Olympus, Kodak and Sony; but no manufac¬
turer claims to be making money out of the
product at this time. So, with much talk —
especially in the Australian market — of fin¬
gers being burnt by the smaller players, the
majors prepared to invest heavily in digital
camera development are still hanging in there.
What is becoming apparent is that digital
camera sales follow on alongside sales of
PCs. A prime case at the moment is New
Zealand, which is showing eager growth in
both product lines.
The Web is also driving digital cameras;
the devices’ ability to output a small, ade¬
Rising,
Falling
Kodak’s new top of the range DC260, with a 1.6-
million pixel CCD coupled to a 3X zoom lens.
quate resolution file direct to the computer is
heaven-sent for eager emailers, attaching
all sorts of imagery to their messages. This
writer is forced to admit to flooding the
network last Christmas with 80 worldwide
email messages — photos attached; be
thankful you were not on my list!
Digital cameras are definitely not being
adopted by the happy family snapper
brigade, nor the keen SLR enthusiast — for
obvious reasons: as yet, the quality is ‘not
there’. Many are also put off by the
downloading trauma and the fid¬
dling needed to extract photo quali¬
ty from current inkjet printers.
But, with regard to the latter,
inkjet printers are winning a multi¬
tude of friends every moment of
every day; new models by HP, Canon
and Epson are outputting colour and
resolution indistinguishable from con¬
ventional colour prints in many
respects. It is a bit of a fiddle — but
one that this writer for one is
happy to undertake!
Nikon’s Coolpix 900 not only features a
swivelling case, for flexibility, but also a
1.3M pixel CCD and a nine-element
Nikkor lens.
14
ELECTRONICS Australia, September 1998
Sharp-eyed sensors
Megapixel models
The current buzz in the industry
centres around which manufacturer
has launched a megapixel camera or
even a ‘megapixel plus’ model.
Megapixel? Basically the term means
a camera able to output a file of one mil¬
lion pixels. In most units at this level the
CCD itself possesses one million picture
elements (pixels) so the output is a gen¬
uine megapixel picture. But some do
Above left is the Olympus C-1400L, which
boasts a 1AM pixel CCD coupled to a 3X
zoom lens; above right is the Fuji MX-700,
with a 1.5MB CCD and a 35mm equivalent
lens; and below is the Konica Q-M100,
with a 1.08M pixel CCD and 6mm lens.
At this point in a maturing market, the
appeal of a CCD of megapixel — or bet¬
ter! — resolution is undeniable. If you are
making digital camera images for repro¬
duction in a glossy colour magazine
(using a 150 lines per inch dot screen), a
1280 x 1024 pixel image will permit
acceptably sharp reproduction to 10.8 x
8.67cm. If sharp-eyed critical assessment
— and the test charts — are put aside, it is
possible to get a very acceptable A5 (half
A4) printed image.
For the home and office user, an image
from a camera of this resolution level is
easily enlarged to near-A4 page size with
high level printers such as Epson’s Photo
EX inkjet, which boasts 1440 dots per inch
resolution on the ‘photo gloss’ paper.
What comes into play is viewing distance
for photographs and the like; nobody
peruses a 10 x 8 (or an A4) print at less
than arm’s length.
‘fudge’ — like the Kodak DC 120 model,
which in truth has an 836,000 pixel CCD,
but outputs a 1280 by 960 pixel picture com¬
posed of 1,228,000 pixels (1.23M) —
accomplished by in-camera interpolation.
Other Kodak models — the DC200 and
DC210 — have actual 1.01M CCDs
(1152 x 864 pixel images).
The newish Fuji MX-700 model
boasts a 1.5M pixel CCD (1280 x 1024
pixel image), while its companion
model the DS-300 offers 1.3M (1280 x
1000 pixel image).
Konica has its Q-M100, with a
1.08M CCD (1152 x 864 pixel image)
- a straightforward camera embell¬
ished by a bevy of Photoshop plug-ins
to titillate captured images.
Nikon, in its 1.3M CCD Coolpix 900
camera, delivers a 1280 x 960 pixel image
with the added cachet of a nine element/seven
group Nikkor lens using aspheric glass ele¬
ments. Three exposure modes are to hand —
spot, centre-weighted, matrix.
Raising resolution...
As digital camera manufacturers strive to
lift resolution levels, camera software devel¬
opers are also seeking to help the cause.
It seems that fractals may provide
some of the solutions. As mentioned in
the text, some cameras employ pixel
interpolation to raise their image cap¬
ture’s apparent overall resolution. This
action relies on internal processing to cre¬
ate new additional pixels, derived from
adjacent CCD pixels.
An exciting approach has also been pur¬
sued by the US Altamira Group. In creating
Genuine Fractals, the company has devel¬
oped a plug-in for Adobe Photoshop soft¬
ware which allows the creation of very
small files from comparatively large files,
and vice-versa. It’s essentially a lossless
compression system. As an example, a
640 x 480 pixel image of 307KB could be
created from a 2000 x 1500 pixel file of
around 8MB, and scaled up again at will.
Whilst not being taken up by any camera
manufacturer at this stage, fractal tech¬
niques look likely to help reduce the size of
images transmitted via the Internet — yet
maintain and even improve their quality.
Believe it! You can download a free trial
version from the company’s Web site at
www.altamira-group.com.
...and lowering it again!
Some camera designers (or is it the
marketing people?) seem to have missed
an essential point in digital camera strat¬
egy: getting the resolution levels up —
and with it, final picture sizes — is the
name of the game.
In spite of this, the dreaded ’digital zoom’
facility has crept in from the world of video
camcorders (where levels of digital zoom
have reached 100X and more). So we see
digital still cameras from Epson, Casio and
others incorporate this feature. (All a digital
zoom does is effectively crop the CCD sen¬
sor image, using digital enlargement of the
centre portion. This essentially throws
away’ some of the sensor’s resolution...)
The Epson PhotoPC 600 offers a 3X dig¬
ital zoom, while the yet to be released PC
700 pulls this back to 2X. In the US and
Japan Casio’s QV-5000SX has a 2X/4X
digital zoom; the Fuji MX-700 features a
‘playback zoom’ of up to 4X, which allows
you to closely inspect a shot — but at
least it does not crop and enlarge the
pixel array as with the Epson models.
Enlarging, say a 1024 x 768 picture by
2X seems a pointless exercise when you
can do it with far more control in image
editing and manipulation software.
Besides, who really wants to throw useful
pixels away when in fact you need every
one you can get!
ELECTRONICS Australia, September 1998
15
Digital Cameras Update
SONY
At the top end
Olympus long ago found its place in the
top three by devoting considerable atten¬
tion to the lens optics in its models. The C-
1400L uses a 2/3-inch CCD (most other
models use a 1/3” CCD) containing
1,410,000 pixels, creating a 1280 x 1024
pixel image. The lens is all-glass and uses
aspherical elements to apply a high level
of correction; its optical resolution of 160
lines/mm at the centre is close to that of
topline 35mm compact film cameras.
Obviously aware that the educated buyer
was flocking to the Olympus, Kodak
moved into high gear a few months ago by
releasing two new cameras.
The Kodak Digital Science DC220 and
DC260 zoom digital cameras are the first
consumer digital cameras to use a
Motorola PowerPC processor to speed
image processing and customise camera
operations. The DC220 has near-one mil¬
lion pixels (an image of 1152 x 864); while
the DC260 has a 1.6 million pixel CCD
(1536 x 1024) and can capture enough
detail for a photo-realistic 8 x 10” picture.
Other niceties include a Burst Feature
which can capture in each second up to
eight pictures at standard resolution or two
pictures at high resolution.
Both cameras allow you to record audio
to accompany your photos. A scripting
Above is Sony’s Digital Mavica MVC-
FD71, which although offering only 640 x
480 resolution also boasts image storage
on standard 1.4MB floppy disks. At left is
their Mavicap floppy disk recorder, which
captures to a floppy disk any image from
a PAL camcorder or any video source
with an analog output.
feature can instruct your camera to per¬
form a series of pre-set actions, such as
take multiple pictures at pre-set intervals
or adopt program camera settings for dif¬
ferent picture-taking conditions.
The DC260 has a lens with 3X optical
plus 2X digital zoom — this means the
unfastidious can ‘zoom in’ to 6X; the
camera offers a useful extra in that it can
connect to an external flash, allowing
lighting of increased subtlety and power.
And notice the very different aspect ratio
of 1.5:1 — identical to a 35mm frame.
Spreading the resolution
A novel and quite fascinating piece of software, PhotoVista
(from Live Picture), comes to the rescue of all those keen to
create sectional panoramas — and so magnify camera resolu¬
tion levels.
You begin by shooting a series of linking and overlapping still
shots. These can be made with a digital or traditional camera
and either input directly from the camera or converted by scan¬
ning. The software then embraces the separate pieces of the
panorama and 'stitches’ together all sections to make a com¬
plete, seamless wide image.
To use it is to be amazed at the ingenuity that has obvious¬
ly gone into its creation; overlapping straight lines meld, hori¬
zons blend, adjoining textures merge. The software (Win and
Mac) costs $145 (Maxwell Imaging is the distributor).
Other makers in the US have created similar applications,
while Olympus and Canon market camera models which have
a panorama stitching feature that produces output similar to
PhotoVista.
16
ELECTRONICS Australia, August 1998
Sony’s Digital Mavicas
While this story is ostensibly about
megapixel cameras, the inescapable fact is
that the whole market is being led by a cam¬
era offering only a maximum 640 x 480
pixel image. The Sony Digital Mavica — in
two models — accounts for 40% of total dig¬
ital camera sales worldwide.
The attraction is that the Digital Mavicas
use the humble, venerable, universal (and
cheap) 3.5-inch HD floppy disk for image
storage. It’s hard to beat the convenience of
shooting a batch of pics, discharging the
floppy and then dropping it into your PC’s
drive to look at them.
And what about the price? Other cameras
use PC cards which can cost in the hun¬
dreds of dollars. A floppy can cost as little
as 50 cents...
Now the company has delivered to market
two new models, the FD51 and FD71 —
plus a clever unit, the Mavicap, based on
Mavica internals.
The higher level FD71 has a progressive
scan CCD and a new, thin high-speed floppy
disk drive, nearly doubling the speed of
recording and playing back images. The
camera’s ‘whole disk copy’ mode also
makes a copy of an entire disk full of
images, with some dexterous disk swapping.
The FD71 has internal RAM to accomplish
this task — and the feature is not limited to
images. Other computer files can be copied
from disk to disk as well.
The new camera’s standard mode saves up
to 40 pictures on a single floppy disk as 640
x 480 PC JPEG files, while the fine mode
stores up to 20 at half the compression of the
standard mode. For higher-quality pictures,
a non-compression mode stores images as a
near-megabyte BMP file.
The FD71 also has an e-mail mode that
reduces the size of the image to 320 x 240
for smaller file size and faster transmission.
Borrowing on Sony’s camcorder exper¬
tise, the Mavica has a 10X optical zoom
lens, macro capability and a manual focus
ring for accurate focusing; and a full-
motion, 2.5” colour LCD display
viewfinder with a solar window. The solar
window uses sunlight to enhance backlight
for the display, for better viewing in bright
light with minimal battery drain.
The camera has a huge advantage in the
digital still camera market by employing a
camcorder battery — the rechargeable
InfoLithium unit that powers the taking of
up to 500 consecutive shots.
Although it’s not a camera, the Mavicap
Floppy Disk Recorder is interesting
because it allows capture of any image from
a PAL camcorder or any video source with
an analog output, and storage on a standard
floppy disk. In effect, then, the floppy disk
recorder transforms a camcorder into a dig-
ELECTRONICS Australia, September 1998
Table 1: A Comparison of Current Models
Manuf/Model Lens Shutter Speeds Pixels/Resolution Viewfinder Price(RRP)
Apple
QuickTake 200
f2.2/5.7mm
1/4-1/5000
350k/640x480
LCD
$995
Agfa
ePhoto 307
f4/6mm
1/8-1/10,000
307k/640x480
Opt.
$699
ePhoto 780
f4/33mm
1/30-1/10,000
350k/1024x768
Opt/LCD
$999
ePhoto 1280
3X zoom
1/4-1/500
810k/1280x960
LCD
$1799
Canon
PowerShot 600
f2.5/7mm
1/30-1/500
570k/832x608
Optical
$1299
Casio
QV-ll
f2.8/5.2mm
1/8-1/4000
250k/320x240
LCD
$499
QV-100
f2.8/4.2mm
1/8-1/4000
360k/640x480
LCD
$899
QV-300
f2.6/4.9-llmm
1/8-1/4000
360k/640x480
LCD
$1399
Epson
Photo PC600
f2.8/5mm
1/4-1/500
810k/1024x768
Optical
$1299
Fuji
DX-5
f3.1/5.7mm
1/4-1/5000
350k/640x480
Optical
$699
DX-7
f3.1/5.7mm
1/4-1/5000
350k/640x480
Opt/LCD
$899
MX-700
f3.2/35mm
1/4-1/1000
1.5MB/1280xl024
Opt/LCD
$1699
DS-300
f2.5/33-105mm 1/4-1000
1.3MB/1280xl000
Opt
$3860
Hanimex
DigiPix
f5/5mm
1/30-2000
350k/320x240
LCD
$499
Kodak
DC50
f2.5/37-lllmm 1/16-1/500
380k/765x504
Opt
$1050
DC120
f2.5/38-114mm 1/16-1/500
836k/1280x960
Opt/LCD
$1650
DC200
f4/39mm
1/2-1/362
1.01MB/1152x864
Opt/LCD
$1250
DC210
f2.5/29-58mm
1/2-1/362
1.01MB/1152x864
Opt/LCD
$1650
DC220
f4-16/29-58mm 1/2-1/360
1.01MB/1152x864
Opt/LCD
$1999
DC260
f3-22/38-115mml/4-l/400
1.6MB/1536xl024
Opt/LCD
$2499
Konica
Q-Mini
f2.8/6mm
1/4-1/2000
350k/640x480
LCD
$899
Q-M100
f2.8/6mm
1/8-1/500
1.08MB/1152x872
Opt/LCD
$1200
Minolta
Dimage V
f5-5.6/2.7X zoom1/30-1/10,000
350k/640x480
LCD
$1099
Nikon
Coolpix 100
f4/6.2mm
1/45-1/10,000
330k/512x480
Opt/LCD
$699
Coolpix 300
f4/6.2mm
1/30-1/2500
330k/640x480
Opt/LCD
$999
Coolpix 600
f2.8/5mm
1/4-1/2000
800k/1024x768
Opt/LCD
$1195
Coolpix 900
f2.4-3.6/5.8-17.4mml/4-l/750
1.3MB/1280x960
Opt/LCD
$1895
Olympus
C-420L
f2.8/5mm
1/4-1/10,000
350k/640x480
Opt/LCD
$979
C-820L
f2.8/5mm
1/4-1/500
810k/1024x768
Opt/LCD
$1299
C-840L
f2.8/5.5mm
1/2-1/500
1.31MB/1280x960
Opt/LCD
$1499
C-1000L
2.8/3X zoom
1/4-1/10,000
850k/1024x768
TTL/LCD
$1999
C-1400L
f2.8/3X zoom
1/4-1/10,000
1.41MB./1280xl024
TTL/LCD
$2499
Pentax
EI-C90
f2.8/5.2mm
1/8-1/1000
410k/768x560
Opt/LCD
$999
Ricoh
R DC-300
f3.8/4mm
1/4-1/16,000
350k/640x480
LCD
$799
RDC-300Z
f3.8/5-15mm
1/4-1/16,000
350k/640x480
LCD
$999
RDC-4300
f2.8-4.7/5.6-16.8mmNA-l/500
1.32MB/1280x960
LCD
$1799
Sanyo
VPC-G100
f2.8/5mm
1/4-1/10,000
350k/640x480
Opt/LCD
$899
VPC-G200
f2.8/5mm
1/4-1/10,000
350k/640x480
Opt/LCD
$1299
VPC-X300
f2.8/5mm
1/4-1/500
810k/1024x768
Opt/LCD
$1399
Sony
MVC-FD51
f2/4.8mm
1/60-1/4000
380k/640x480
LCD
$1149
MVC-FD71
fl.8/4.2-42mm
1/60-1/4000
380k/640x480
LCD
$1599
Notes: Some cameras appear on the market as rebadged models: Konica’s Q-mini, Canon PowerShot
350 and Panasonic’s DCF1A are, for all intents and purposes, identical — as is Hewlett-Packard’s HP.
17
Digital Cameras Update
ital still camera.
The unit has composite and S-video
in/outputs.
So where are we?
There’s no doubt that digital cameras are
now, from a marketing point of view, a
viable product. In Australia alone sales in
1998 are expected to reach 35,000 — up by
40% from 1997’s 25,000 figure.
They are being increasingly accepted in
business and education circles; because of
this, there is possibly less criticism applied
to their technical shortcomings.
All the same, it’s doubtful if a keen ama¬
teur photographer, let alone a pro, would
accept their remaining deficiencies. Like:
• Virtually all of the latest digi cams sport
an LCD finder; these draw power at an
alarming rate. The hapless alkaline cells
frequently supplied with digi cams are
totally inadequate for the task. The ideal
CMOS sensors?
In our previous report on digital
cameras (EA December 97), mention
was made of the attractions of CMOS
image sensors,
Vivitar's ViviCam 3100 is attracting
attention in the US. It has an 800,000
pixel CMOS sensor, with a 1920 x
1600 pixel output image, and is
claimed to offer 'advanced 30 bit, four
colour performance’...
answer seems to be the camcorder batter¬
ies employed by Sony and Canon in their
new models; high shot numbers and easy
recharging are their attractive benefits.
• The rated speed of all consumer camera
CCDs is far too low for general use;
Nikon’s Coolpix 900 camera rates its
CCD as equivalent to ISO 64 remem¬
ber Kodachrome 64? Most other models
go only to ISO 100, which is still not too
wonderful.
• In poor light conditions the built-in flash
can save the day — but most are too low
in output for wide shots.
• The opposing standards of PC memory
cards — SanDisk’s CompactFlash and
Toshiba’s SmartMedia — is a problem.
Some cameras use one, the rest use the
other — with no converter between. Now
Above is a night shot taken with the Fuji
MX-700, which sports an image resolution
of 1.3 million pixels. At left is an image
taken with the Nikon Coolpix 900 camera ,
which offers an image resolution of 1280
x 960 pixels. Below is a shot of the
Braidwood hotel , taken with a Kodak
DC200 — with 1.01 megapixel CCD (1152
x 864).
it seems likely Sony will develop a
‘super-floppy’ capable of 200MB!
It will certainly be interesting to see
what the future holds in this fast-moving
market area.
(Barrie Smith is editor of Australian
Digital Camera magazine.) ❖
18
ELECTRONICS Australia, September 1998
Hong Kong
ELECTRONICS
Oct 13-16, 1998
Hong Kong Convention &
Exhibition Centre
There is no better place to obtain the latest on electronics than Hong Kong
Electronics Fair '98. Over 1,200 exhibitors will be there to show consumer
electronics, electronic components and technology. In addition, there are
numerous concurrent events to satisfy buyers' needs:
• "The Frontiers of Brainpower" - for innovative concepts, prototypes of
technology and product research with ample opportunities for business
partnerships
• "electronicAsia" - jointly organized with Germany's Messe Miinchen
International (MMI), for electronic components, assemblies and
production gear
Organizer:
SU sisni»Kfi
Hong Kong Trade Development Council
• "LaserAsia" - a Asian trade fair for laser technology and technical optics,
co-organized with MMI
• "Asian Electronics Forum" - for the latest market trends and technological
developments
Level 3, Hong Kong House
80 Druitt Street
Sydney N.S.W. 2000
Australia
Tel : 61 -(02)-9261 -8911 Fax : 61 -(021-9261 -8966
E-mail : exhibitions@tdc.org.hk
Web Site: http://hkelectronicsfair.tdc.org.hk
Official Air Express Co.:
• "PCIM Conference" - for Power Electronics, Drives, Motion and Control
Be ready for the 21st Century. Be there at Hong Kong Electronics Fair '98.
Fair Opening Hours
October 13
9: 30am -
10: 00 pm (Opening Ceremony)
10: 00am -
6: 30pm
October 14-15
9: 30am -
6: 30pm
October 16
9: 30am -
5: 00 pm
Official Carrier:
Cathay Pacific
Trade only. Visitors under the age of 18 will not be admitted.
Olympus
Camedia C-1400L
Digital Camera
There’s no doubt that Olympus is
continuing to take a leading role
in the accelerating development
of digital cameras. We recently
had the opportunity to try out its
current flagship model, the C-
1400L — boasting a 1.4-million
pixel CCD sensor, coupled to a
3X power zoom lens with true
TTL single-lens reflex viewfinder,
and using SmartMedia
removable memory cards.
by Jim Rowe
W hen I reviewed the Olympus C-800L
digital camera this time last year, I
wrote in the summary box “If it had a
zoom lens for easier closeups, an SLR-type
viewfinder and perhaps could take extra plug¬
in cards for even more memory, our wish list
would be totally fulfilled”.
Well, with the new C-
1400L they’ve come very
close to doing it.
The C-1400L has an
all-glass seven element
3X power zoom lens,
covering the focal length
range of 9.2 - 28mm
(equivalent to 36
110mm in familiar 35mm
camera terms), and with a
maximum aperture vary¬
ing from f/2.8 at the wide
angle end to f/3.9 at the
tele end. The rated resolu¬
tion of the lens in the cen¬
tre is better than 100
lines/mm, higher than the
lenses in many 35mm
SLRs. And it has a true
SLR-type TTL (through
the lens) optical viewfind¬
er, for parallax-free image
composition. It even has plug-in SmartMedia
memory cards, although these are now
instead of the fixed internal 6MB memory in
the C-800L, rather than in addition to it. Oh
well, we can’t have everything, I guess...
On the other hand, the C-1400L does have
a new and improved 17mm (2/3”) progres¬
sive-scan 1.4 million pixel CCD image sen¬
sor, delivering a maximum image resolution
A handheld shot (HQ mode) with the
zoom lens at the tele end, taken on the
seashore of Botany Bay, on a dull
afternoon.
of 1280 x 1024 pixels. That’s an improve¬
ment of about 66% over the interlaced-scan
CCD used in the C-800L, which delivered a
maximum resolution of 1024 x 768 pixels.
And the progressive-scan technology does
provide improved colour rendition and
reduced fringing.
As before, the C-
1400L offers such nice
features as autofocus (by
contrast detection), spot
TTL exposure metering
and compensation for
back lighting (seven
steps). The lens also fea¬
tures a special Olympus
compact prism for the
SLR system, reducing
overall weight and elimi¬
nating the moving mirror
and its mechanical shock.
The lens again has a
macro range, focussing
from 300mm to 600mm
in addition to the normal
range of 600mm - infin¬
ity. This doesn’t let you
get quite as close as the
200mm of the C-800L,
but on the other hand the
longer focal length brings you visually
closer. There’s two ‘Quick Focus’ settings
of either 400mm or 2.5m, to speed up
20
ELECTRONICS Australia, September 1998
shooting in typical situations.
The zoom lens fitted to the C-1400L
actually seems to have only two aperture
settings, f/2.8-3.9 and f/5.6-7.8. The
remaining exposure adjustment seems to
be via shutter speeds,
which vary between 1/4
and 1/10,000th of a sec¬
ond. Not that the user is
normally aware of this,
of course. The effective
sensitivity of the cam¬
era’s CCD sensor is
ISO 100 — not super
sensitive, but OK for a
lot of photography.
As noted the C-1400L
stores its images in slim
SmartMedia removable
memory cards (also
known as SSFDCs or
‘Solid State Floppy Disk
Cards). These operate on
3.3V and are made by
Toshiba. They slip into a
slot at the right-hand rear
of the camera, accessed
via a swing-out door.
The C-1400L comes
complete with a 4MB card which can store
between four and 49 images depending on
the resolution mode you’ve set.
There are three resolution modes avail¬
able on the C-1400L, labelled SQ, HQ and
SHQ in ascending order of effective image
resolution (and file size/downloading time).
SQ or ‘standard quality’ gives 640 x 512
pixel images, and it’s this mode in which the
4MB memory card will store 49 images.
The HQ or ‘high quality’ and SHQ or ‘super
high quality’ modes both deliver images of
1280 x 1024 pixels, but with greater or less¬
er amounts of compression respectively. It’s
in the SHQ mode that the 4MB card will
only store four images; in HQ mode this
rises to 12 images.
So although the C-1400L does offer con¬
siderably better image resolution than say
the C-800L, plus the convenience of
SLR/TTL operation and a zoom lens, there
is a price to pay in terms of image storage
with the included 4MB memory card. With
the C-800L, you could store up to 30
images of 1024 x 768 pixels in the built-in
6MB memory.
Of course with the C-1400L you can
always get additional 2MB and 4MB
cards, and swap cards as they become
filled. Olympus also notes in its literature
that 8MB and larger cards are likely to be
available soon.
Another important advantage of using the
removable SmartMedia cards is that they
provide an additional avenue for download¬
ing the images to your computer. In fact one
of the optional accessories Olympus has
available for use with the C-1400L and its
other models using SmartMedia memory
cards is a special adaptor which accepts the
cards and slips into a standard 3.5” floppy
disk drive, to allow the PC to read from and
A closeup taken with the macro facility, at
minimum distance. The colour
temperature is low as incandescent
lamps were used.
write to them directly, as if they were a flop¬
py. (You need to load a small driver utility to
do this — the utility is supplied on floppy as
part of the adaptor kit.)
Downloading images via the card adaptor is
potentially rather faster than using the RS-
232C serial cable system used with the C-800L
and other earlier models, but the C-1400L still
provides this option if you prefer. Or if you
have a machine running Windows NT4, with
which the adaptor utility
isn’t compatible...
By the way the C-
1400L also has a high
speed parallel output
port, which can be used
to download images
directly to the optional
Olympus P-300E dye
sublimation printer. That
way, you can get colour
prints immediately, with
no need for a PC.
The C-1400L also
includes a flip-up variable
output electronic flash,
with three operating
modes: autoflash (fire
when needed), fill (always
flash) and red-eye reduc¬
tion (multiple flashes, to
reduce a subject’s pupil
size). Needless to say the
flash is automatically dis¬
abled in the ‘down’ position.
Other features continued in the C-1400L
include a 45mm diagonal TFT colour LCD on
the rear of the camera, to allow convenient
reviewing of the shots you’ve taken; automatic
time and date ‘stamping’ of each shot; the abil¬
ity to selectively erase unwanted shots from
memory, to free space for more shots; and
focus locking with the release button pressed
halfway in. As with earlier Olympus models
At the rear,
there ’s a
45mm TFT
LCD screen for
reviewing your
pictures, as well as
the TTL viewfinder —
which has dioptre
adjustment, by the way.
The camera is quite
intuitive to use.
ELECTRONICS Australia, September 1998
21
READER INFO NO.8
Olympus C-1400L Review
Olympus Camedia C-1400L Digital Camera
An advanced digital still camera taking images at up to 1280 x 1024 pixel
resolution. Features a seven-element 3X power zoom lens (equivalent to 36 -
110mm on a 35mm camera), with true SLR-type viewfinder, autofocus and TTL
spot metering. Stores images in removable SmartMedia memory cards. Built-in
flash and 45mm colour TFT LCD screen for reviewing images.
Good points; High image resolution, colour rendition with improved progressive
scan CCD sensor; zero parallax error with SLR viewfinder. Fast image downloading
via SmartMedia floppy adaptor. Basically, excellent image quality and operating
convenience.
Bad points; Very little, apart from the price.
RRP: $2499.
Available: From digital camera dealers, some photographic stores. For your nearest
supplier contact distributor R. Gunz (Photographic), 2/26-34 Dunning Avenue,
Rosebery 2018; phone (02) 9935 6600 or fax (02) 9935 6622.
it’s powered from four AA-size batteries, of
either the alkaline or NiMH or NiCad type.
The C-1400L is compact, measuring 115 x
130 x 83mm and weighing a modest 470g
without batteries or memory card. It comes
complete with lens cap, carrying strap, bat¬
teries, RS-232C serial cable (with Mac adap¬
tor), a 4MB SmartMedia card, manuals and
two CD-ROMs containing the Olympus util¬
ity software and a bundled image editing
application (Adobe’s Photo Deluxe).
Options available include an AC power
adaptor, a set of NiMH rechargable batteries,
a battery charger to suit, a carrying case, the
SmartMedia floppy adaptor kit and of course
the P-300E colour printer.
Trying it out
Olympus distributor R. Gunz (Photographic)
very kindly made a sample C-1400L available
for a few days, so I could try it out for myself.
I was able to try it in a variety of situations,
and compare its performance with other cam¬
eras I’ve used of both the film and digital type.
Frankly I’m most impressed. The image
quality is excellent, particularly in the top
SHQ mode but also in the HQ mode. There
seems to be very little of the edge fringing
visible on earlier models, and the colour gra¬
dation also seems a lot smoother.
I have the impression that the zoom lens
sharpness isn’t quite as good as on the C-
800L’s fixed 5mm lens, especially at the
tele end, but it’s still very good indeed.
Hopefully you’ll get at least a reasonable
idea of the image quality possible from the
sample shots included here — which are not
retouched at all, just converted to CMYK
format for printing.
Overall the operating convenience and the
potential image quality achievable with the
C-1400L seem very comparable with a typ¬
ical good quality 35mm SLR. About the
only area of unfavourable comparison now
is cost; by the time you add an extra
SmartMedia card or two for storing enough
shots for a trip or whatever, you’re still pay¬
ing a considerable premium for the conve¬
nience of digital photography. Hopefully
this will continue to improve with time.
All the same, Santa can certainly bring me a
C-1400L if his budget allows. And if you get
a chance to try one out for yourself, you’ll
very likely want one too... ❖
Scan Audio's
1998Speaker Drivers
and Kits Sale.
J)eerlessH^
El
iMiaudio
Peerless, Vi fa drivers up to 50% off!
Dynaudio drivers up to 50% off!
Presenting our annual sale for 1998. We welcome your enquiry & order by telephone fax, or e-mail. One flat delivery
fee of $10.00 applies to each order. Orders despatched next business day. Data on these drivers is available in our
comprehensive 106 page catalogue with full factory data sheets on every Vifa, Peerless, Dynaudio and Scan-Speak
driver we sell. Catalogue costs $15.00 which includes air mail postage anywhere in Australia or New Zealand.
VISA
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READER INFO NO.9
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Reader Info. No 10
Moving Peop.
Safely
with Electronics 1
This is the first of two articles discussing the development of electronic solutions in automotive
safety applications. As well as an insight into the actual operation of the systems, the enabling
technologies which facilitate them will be discussed in order to give the reader an
understanding of their complexity. In addition to the better-known systems such as ABS and
Airbags, we’ll also be covering systems which are currently regarded as ‘niche’, along with
advanced safety systems of the future.
by Ross Bannatyne,
Motorola Transportation Safety & Chassis Systems Division
S afety systems in automobiles have
evolved considerably in the last 100
years. Around 1900, the round steer¬
ing wheel made its debut, oil and gas pow¬
ered lighting was replaced by electric
lamps in 1912 and the 1920s saw the pop¬
ularity of much safer ‘closed’ cars, com¬
plete with a roof.
The last century has also seen hydraulic
braking systems replace crude cable or rod-
based systems, the introduction of seat belts
(a major safety milestone in the 50s), and
the electronic age arrive in the 60s and 70s,
to herald a new revolution in automotive
safety system improvements.
Chassis control systems
There are several electronically controlled
chassis systems which enhance safety by
optimizing the interface between the tires
and the road surface — either in the longitu¬
dinal, lateral or vertical directions. Fig.l
illustrates the popular chassis control sys¬
tems and the associated directional dynamics
on which they act.
To optimize dynamic stability in the lon¬
gitudinal direction, there are three popular
systems: antilock braking systems (ABS),
four wheel drive (4WD) and traction control
systems. Note that conventional 4WD sys¬
tems typically use a transfer box with vis-
Safety features of current model Holdens
include airbag protection for both front
passenger and driver, activated by
deceleration sensors.
(Courtesy Holden Ltd.)
cous coupling which operates when a differ¬
ence in the speed of rotation between front
and rear wheels occurs. The electronically
controlled system is more efficient, as con¬
siderable slip is not required before the 4WD
operates and a better optimization of drive-
line torsion, traction and braking capacity
may be achieved.
In the vertical direction, roll stabilization
and active-suspension systems may be
implemented, although these are still in their
infancy in terms of the actual number of
vehicles which include such systems. A sen¬
sor to detect the roll motion of the vehicle
could also be employed in order to imple¬
ment a rollover protection system, enabling
the deployment of hidden rollover bars in a
convertible in the event of an accident. The
same sensor could be used with the airbag
system in order to determine when a roof
airbag should be fired, as well as the new
‘inflator curtain’ type airbags which protect
occupants from glass splinters and intrusion
during a rollover crash.
Lateral stability is the third directional
dynamic factor in overall vehicle chassis
control and safety. As well as four-wheel
steering (4WS), which increases stability
whilst cornering at high speed, new systems
are being introduced to compensate for
24
ELECTRONICS Australia, September 1998
Not surprisingly, Volvo’s new S80 boasts a raft of safety features, with electronics playing
a crucial role. The company has enhanced its SIPS (Side Impact Protection System) with a
new Inflatable Curtain, which inflates in 25ms to increase protection against head and neck
injuries. (Courtesy Volvo Car Australia)
understeer or oversteer by the driver. The
industry has settled on the name ‘electronic
stability program’ (ESP) for these systems,
after being referred to as many names such
as Integrated Vehicle Dynamics, Automatic
Stability Management Systems, and others.
ESP will be discussed later in this article.
Taking the concepts of ESP slightly fur¬
ther, a fully integrated chassis control system
would control the functions of suspension,
steering and braking seamlessly and would
require real-time information on all six
degrees of freedom of the vehicle as
well as information on the status of each
system’s control variables and a real¬
time communication link with other rel¬
evant systems such as the powertrain. It
is normal today for the traction control
system to communicate to the power-
train system in order to adjust throttle
angle whilst applying braking forces to
achieve optimum traction. It is expected
that one system will control the inter¬
operability of all of these related sub¬
systems in the near future.
Antilock braking
The first electronically controlled safety
feature which became mainstream was
antilock braking systems (ABS). The
historical significance of this system is
notable — ABS is arguably the most
important advancement in automotive
braking technology since the develop¬
ment of hydraulic braking.
After early mechanical implementation of
ABS in trains and aircraft, analog-based con¬
trollers were implemented on several vehi¬
cles in Europe and the United States. The
analog-based units however had limited per¬
formance capabilities, were not completely
reliable, and were expensive. Digitally con¬
trolled ABS systems were adopted in the 80s
and had excellent performance, excellent
reliability and increasingly lower costs. A
block diagram of an ABS Electronic Control
Unit is shown in Fig.2.
The block diagram is generic and it should
Fig.1: Modern vehicles include electronic
systems which control and stabilise
chassis movement in all three axes.
be noted that there is an almost infinite combi¬
nation of how the main functions can be parti¬
tioned in silicon chips. The most common
approach is a mix between established ‘off-
the-shelf products and custom devices such as
advanced ASICs. In certain cases a cus¬
tomized silicon solution can lead to a signifi¬
cant competitive advantage.
There is a clearly defined relationship
between the slip ratio of the wheels and the
coefficient of friction of the road surface.
The ABS control system uses informa¬
tion on the wheel speeds to determine
the slip ratio, and subsequently ensure
that the maximum grip is applied to the
road surface in the longitudinal direc¬
tion — and also that the grip is opti¬
mized in the lateral direction when cor¬
nering. An algorithm is executed in the
microcontroller to determine slippage
and determine how the brake pressure
should be maintained at each wheel.
The wheel speed sensors are still
most commonly the variable reluc¬
tance type, which are robust, low cost
and well suited for the harsh environ¬
ment/high temperatures at the wheel.
But they do require considerable inter¬
facing. After signal conditioning, the
stream of pulses generated by the
wheel speed sensors are then fed into
timer input channels on the MCU.
A ‘fail-safe’ microcontroller, shown
in Fig.2, is used for plausibility checks
and to process certain parts (or some¬
times all of) the algorithm in parallel with the
main micro. This is to ensure that any possi-
A Active Suspension
I Roll Stabilization
4 Wheel Steering
ESP (Electronic Stability Program)
ELECTRONICS Australia, September 1998
25
Moving People Safely
Fig.2: Block diagram of a modern ABS (anti-lock braking system) electronic control
unit. The serial comms interfaces are for communication with other vehicle systems.
ble failure modes associated with the ECU
can be determined by the system. If a failure
mode is detected, a relay will be switched to
disconnect the electrical system, so that the
ABS is disabled and the conventional
hydraulic braking (unassisted by ABS)
remains. In this respect, the ABS system is a
supplementary system which behaves in a
fail-silent way should it detect any faults. A
warning light is also switched on and often a
fault code will be loaded into EEPROM on
the MCU.
It’s now common for ABS systems to
share information with other vehicle sys¬
tems; hence the requirement for high speed
serial communications. For example, the
wheel speed information may be sent to the
Navigation controller and the throttle pedal
travel/position information will often be
acquired from the powertrain controller.
Airbag system
The other key electronically controlled safe¬
ty system on today’s vehicle is the supple¬
mentary restraint or airbag system. Driver
and passenger airbags are standard in almost
all new vehicles today, with more and more
vehicles featuring seat belt pretentioners and
side impact airbags. The next step is ‘smart’
airbags which will sense occupant position
and crash severity. These additional sensors
will allow the system to tailor the deploy¬
ment using multi-stage or variable inflators
to optimize occupant protection under a
wider range of conditions.
Because of the growth in the number of
actuators and sensors for smart airbag sys¬
tems, a distributed airbag system has been
proposed which uses a common chipset and
communications technology, allowing mul¬
tiple airbags to be connected to the system
easily. The key driver in the development of
this system was robustness and reducing the
cost. The standard components and inter¬
faces allow expandability, flexibility and
reduce the airbag system suppliers time-to-
market. The distributed airbag concept is
shown in Fig.3.
The system is composed of bus systems
which allow easy integration of a number of
airbags, switches, sensors or belt tensioners.
The buses have been optimized specifically
for the airbag application. The electronic
control unit in the middle of the diagram
includes an MCU for processing the crash
detection algorithm, an accelerometer for
detection of a crash and a ‘safing’ sensor.
The safing sensor provides redundancy for
added safety, just as the redundant micro¬
controller in the ABS system performs a
‘fail-safe’ function. The safing sensor is con¬
nected with the firing circuit in such a way
that it establishes a logical AND connection.
Any firing action of the system remains
without effect unless the safing sensor
How the Inflatable Curtain in Volvo’s new S80 protects against
head and neck injuries. Sensors in the B-pillar and rear wheel
arches inflate the curtains within 25ms of a side impact.
(Courtesy Volvo Car Australia)
Fig.3: Block diagram of a modern distributed airbag system,
showing the way multiple sensors and airbags can be
connected. Standard components and interfaces allow
expandability and flexibility, and reduce costs.
26
ELECTRONICS Australia, September 1998
agrees with the algorithm which operates on
the accelerometer signal.
In addition, the system includes a power
supply and drivers for the buses.
Electronic Steering
Although it could be argued that the steering
system is not, strictly speaking, a safety sys¬
tem, there is no argument that it is a safety-
critical system — and as such requires care¬
fully implemented electronic controls. The
steering system will, in the future, be closely
integrated with other chassis control func¬
tions such as braking and suspension con¬
trols, to form an overall chassis control sys¬
tem. For this reason, the steering system has
been included in this article on safety elec¬
tronics; its electrification will one day enable
the integrated system to steer out of trouble
automatically.
There is currently a trend towards imple¬
menting direct-assist electric motor steering
systems, from the more conventional electro-
hydraulic power steering systems. In the event
of a system fault, the direct-assist system
requires additional safety considerations to
ensure that the driver must always overcome
any motor torque required to retain control of
the steering. In this respect, unlike the ABS
system, the direct-assist system must be fault-
tolerant — in the event of a failure, steerabili¬
ty must be maintained. For this reason, addi¬
tional protective elements are designed into the
controller (typically smart diagnostics). Both
systems are shown in Fig.4.
Both systems have similar controller
architectures, which include MCUs and
power stages, although the requirements of
theses components will differ depending on
the motor type and its associated control
strategy. A simple PM (permanent magnet)
DC motor would typically be controlled by
an average performance 8-bit MCU such as a
Motorola M68HC11.
Electronic stability
The industry has now settled on the acronym
ESP to describe the many varied systems
which handle stability management/vehicle
dynamics. The first step in integrated vehicle
dynamics is to introduce lateral stability as an
incremental feature to ABS systems. A lateral
stability ESP system aims to counteract
extreme understeer or oversteer situations.
Fig.5 represents a vehicle in oversteering and
understeering situations. To counteract over¬
steer by the driver, an automatically generated
brake force is applied to the front outer wheel
to generate an outward yaw moment. To coun¬
teract understeer, automatically generated
brake forces are applied to outer front and rear
wheels to reduce vehicle speed and generate
an inward yaw moment. This action greatly
enhances the lateral stability of the vehicle.
A lateral stability ESP system can be imple¬
mented with several additional electronic
Electro-hydraulic power steering system controller
Direct-assist electric motor steering system controller
Fig.4 (above): Block diagrams
comparing an electro-hydraulic
power steering system controller
(top) with one using a direct-assist
electric motor.
Fig.5 (right): An electronic stability
program (ESP) system can be used
to improve the vehicle’s lateral
stability, as an incremental feature
to ABS.
Fig.6 (below): The logical algorithm
used in a typical EPS system. It
can be executed by the ABS
microcontroller.
OverstMring Understeering
Where does the driver want to go?
Where is the car going?
ELECTRONICS Australia, September 1998
27
Moving People Safely
components on top of the standard ABS elec¬
tronic controller. A steering wheel angle sen¬
sor, yaw rate sensor and lateral low-g sensor
must be added. The algorithm (shown in
Fig.6) is executed by the ABS microcontroller
and the wheel speed information is already
available as generated by the ABS system.
Lateral stability ESP is only the first stage of
fully integrated vehicle stability manage¬
ment systems which will, in the future,
integrate together steering, braking
and suspension functions seam¬
lessly whilst interacting sub¬
stantially in real time with
the powertrain system. The
next logical step will be roll
stabilization/active-suspension and then full
active control of the chassis system with
respect to all six degrees of freedom.
An example of an advanced fully integrated
ESP system is shown in Fig.7. A redundant
communications network is employed to
provide fault-tolerant communications in
linking up each individual chassis control
system to a central computer which coordi¬
nates the activities of each system. Typically
a very powerful PowerPC class of microcon¬
troller would be expected to be used for this
overall control function. A communications
link would also be used to communicate with
other systems.
Emergency reporting
As the modem vehicle consists of a number
of bus systems connecting many complex
functions, there is a very high degree of sys¬
tem inter-operability available. One such
example which enhances occupant safety is
an automatic emergency reporting system.
This system links the airbag system with a
wireless communications system and initi¬
ates an emergency call in the event that an
airbag is fired.
An operations centre would receive the
distress signal and the vehicle’s position
would be determined using a navigation sys¬
tem typically employing GPS. Dispatch of
appropriate emergency services can help
avoid further emergency situations.
A/D
i
Pressure J ^
sensor
MCU
A/D
—
EEPROM
for
Data hold
Central ESP System Controller
Communications
-w -"
Redundant
Communications
Electronic Braking
Control System
Electronic Steering
Control System
Electronic Suspension
Control System
Fig.7: An example of an advanced fully integrated ESP system, of the type soon to
become available.
Volvo’s new S80 includes no less than 18 different microcomputers, each dedicated to
a specific function and all linked via multiplexed digital networks. The green CAN
network runs at 125kb/s, while the red CAN network runs at 250kb/s. The remote entry
management system uses rotating access codes and includes an electronic
immobiliser. (Courtesy Volvo Car Australia)
Tyre pressure monitor
Certain ABS system suppliers have, for
some time, offered a system which includes
an algorithm which can detect if a tyre’s
pressure is low. A warning lamp is typically
illuminated to alert the driver to this condi¬
tion. When tyre pressure is reduced, the
rolling radius, or distance that the tyre travels
per revolution changes. This can be detected
using the existing wheel speed sensors.
The introduction of ‘run-flat’ tyres by the
major tyre suppliers will render this algorithm
non-operational, as when a puncture occurs
with run-flat’s, the rolling radius will not
change. For this reason a new system is being
introduced to detect tyre deflation, which
includes a pressure sensor and RF transmitter.
The tyre pressure from each wheel is trans¬
mitted to the receiver, which is shared with
the remote keyless entry (RKE) system.
Additional information may be sent, such
as a wheel identifier. This information can be
used to help determine when to best rotate
the tyres to maintain equal tread wear.
An example circuit used for tyre pressure
monitor applications is shown in Fig.8. The
module is attached to the tyre valve or may
be molded into the tyre wall. A 3V battery
would typically be used to provide power,
although the system would be used in
‘sleep’ mode most of the time, only waking
up every 30 seconds or so to transmit tyre
pressure. FM modulation with a carrier fre¬
quency of approximately 300MHz is used
for these systems.
In the second of these articles we’ll look at
systems for occupant sensing, brake assis¬
tance, collision warning and avoidance, and
also at anticipated future trends in auto safe¬
ty technology.
(To be continued.) ❖
ext.C
Diagnostics
Fig.8: Block diagram for a tyre
pressure monitor, which can be built
into each wheel.
Class C
Powertrain
Body ITS
28
ELECTRONICS Australia, September 1998
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electronics!
Conducted by Jim Rowe
Ionospheric research isn’t new —
and timebase correctors that ain’t!
Let’s have a break this month from such things as ‘alternative electrotherapy’
devices and EM radiation worries from cellphones, and look at a couple of other
topics that have produced interesting reader feedback. One is Tom Moffat’s article
in the May issue about the US military’s HAARP project; the other my own review of
a video mixer in the April issue...
I don’t know about you, but my impression
is that we’ve probably chewed around the
topic of alternative electrotherapies more
than enough — for the time being, at least.
After a while you start going over the same
ground again, don’t you? It starts getting
tedious, and there’s little point to be served
because no one is likely to change their
views once the tedium factor comes in...
Instead I’d thought about revisiting the
subject of possible health risks from cell¬
phones, as I’ve seen some interesting discus¬
sions on the internet. But here again there
isn’t a great deal of really new information;
mainly new ways of looking at things, and an
interesting courtcase or two.
On the other hand a couple of letters have
turned up on quite different topics, both aris¬
ing from articles we’ve published in recent
issues of the magazine. So bearing in mind
that the original idea of Forum was to allow
readers to ‘have their say’ in an extended
sense, reacting to things we publish, I’ve
decided that we’ll look at these instead. I
feel sure you’ll find both letters as interest¬
ing as I did.
The first letter comes from Mr John
Cameron, of Roseville in NSW. Mr Cameron
is responding to Tom Moffat’s feature article
on the US military’s HAARP project, which
we ran in the May issue. Here’s what he has
to say:
I was interested to read Tom Moffat’s arti¬
cle on the US HAARP project in the May edi¬
tion. It brought back memories of my student
days at the University of New England
(UNE) in northern New South Wales. I
thought that your readers may be interested
to know that sites like HAARP have run in
Australia in the past, and they are not as
unusual as Tom implied.
The University of New England (UNE) is
located at Armidale, a sheep grazing area in
New South Wales, about 500 kilometres
north of Sydney. For a number of years from
the late 1960s the University Physics depart¬
ment operated an ionospheric research pro¬
ject involving a very large transmitter
designed to put energy into the ionosphere.
Like HAARP the funding for the project
came largely from the US Department of
Defense, something that was not advertised
in the University environment of the early
1970s. I was involved with the project for a
time in 1973.
The main difference between the
University of New England facility and the
HAARP project is that the university trans¬
mitter beam was not steerable and ran at a
fixed frequency. We had a single large trans¬
mitter and antenna rather than a number of
smaller units.
The transmitters, antenna and a small
number of equipment buildings were located
in a rural area about 10km from the
University. If my memory serves me correct¬
ly the main transmitter was rated at well
over a megawatt in continuous operation
with a pulse power of 2 - 3MW. The trans¬
mitter was powered by its own 66,000 volt
feed from the NSW electrical grid. We were
one of the few private buyers of high voltage
power in NSW.
Metre-tall valves...
While the main transmitter was simple in
design, everything about the transmitter was
large. It looked like a normal transmitter
built using giant components. Most of it was
constructed in a metal lined room. Coils
were adjusted using mechanical linkages
from outside the room. The transmitter
valves stood close to a metre tall.
The antenna was equally large, covering a
number of hectares on tall wooden poles
over a very large copper ground mat. The
antenna directed the transmitter energy
straight up to the ionosphere. I seem to
recall the antenna had a gain of over 30dB.
One big difficulty with using the transmit¬
ter was that it ran in the middle of the broad¬
cast band, at a fixed frequency of just over
1.5MHz. As this single transmitter was prob¬
ably equal in power to the total of all com¬
mercial broadcast band transmitters in
Australia, there were naturally a few restric¬
tions on transmitting. The main transmitter
could only be run from midnight to dawn, but
as a tradeoff we had exclusive use of a nar¬
row range of broadcast frequencies during
the early dawn hours.
Now you may wonder why megawatt trans¬
mitters are needed to research the ionos¬
phere. As you probably know the ionosphere
is a layer around the earth between about 50
and 800km up, that contains sufficient free
electrons and ions to affect radio waves.
When a radio wave travels through the
ionosphere, it sets the electrons into oscilla¬
tion, and these oscillations are dampened by
collisions between electrons and gas mole¬
cules. Above about 100km the collisions are
sufficiently infrequent that for most purposes
their effects can be ignored. This is called
the E and F ionosphere region. In these
regions it is possible to simply determine the
ionosphere characteristics by obtaining
echoes from a range of frequencies. This is
done from the ground or satellites, with a
device called an ionosonde sounder.
But below about 100km the atmosphere
effects things. This is the D region. Here the
collision frequency of electrons with gas
molecules becomes important. This makes
the region much harder to study. One of the
few available technique§Js to send high pow¬
ered pulses at between 1.5 and about 6MHz
into the D region. This energy excites elec¬
trons in the D region. By studying how long
this excited area takes to return to normal it
is possible to understand what is occurring.
The UNE transmitter was used to send
megawatt pulses at just over 1.5MHz into
the D region. Each pulse accelerated elec¬
trons, which then cooled as they collided
with the tenuous gases in the ionosphere. By
sending very short probing pulses from
smaller transmitters through the heated
area and studying the echoes, it was possi¬
ble to determine how slowly the pulse
decayed at various heights. For example it
was possible to analyse the effect of sunrise
on the D region and the resulting major
changes in radio propagation.
30
ELECTRONICS Australia, September 1998
IOWOSPMcRIC fcSSMtH
in -me iSfco's ■•••
The smaller probing transmitters used to
investigate the decay of the main transmitter
pulses were 10 - 20kW transmitters operat¬
ing at about 2.2MHz. These were not origi¬
nally crystal locked, and on more than one
occasion there were friendly calls from the
PMG's Department about an 'unknown
transmitter ' wandering into the 2.182MHz
marine distress frequency and setting off
alarms on ships all along Eastern Australia.
Thus HA ARP is not exceptionally power¬
ful by the standards of ionospheric research.
HA ARP will ultimately run at about 3.5
megawatts and this is not much higher in
power than equipment we had in Universities
here in Australia 25 years ago.
It is possible to guess at how HAARP will
be used without resorting to Death Star'
headlines.
Locating HAARP in Alaska is very inter¬
esting. It is very important scientifically, as
in those regions one can see the conse¬
quences of the interaction of the upper
atmosphere with energetic particles ejected
from the sun (the 'solar wind') and the
earth's magnetic field. Part of the energy
received from the sun in that manner leads to
the production of the Aurora Borealis. Part
of the energy also goes into large electrical
currents flowing in the upper atmosphere at
an altitude of about 100km. These currents
are strong enough and impulsive enough to
disturb the magnetic field near the ground
and to induce ground currents that can be
sufficiently intense to seriously disrupt
ground electrical networks. Currents can
exceed a million amps, spread across a belt
100km wide. The upper atmosphere at the
poles is a very interesting place.
The one original part of the HAARP
research program is to investigate if this cur¬
rent can be modulated at 30 kilohertz or less,
to generate a small low frequency signal It
appears theoretically possible to heat elec¬
trons in part of the ionosphere to change the
upper atmosphere currents by about one part
in a million. This would be enough to gener¬
ate a measurable signal on the ground.
At present the US Navy uses two low fre¬
quency transmitters in the US to cover the
world. Perhaps this is a simpler way to gen¬
erate Extremely Low Frequency (ELF) sig¬
nals. For more information see the Internet
site www.haarp.alaska.edu.
Other claims made
Tom's article mentioned that ‘according to
people who have sighted HAARP internal
documents, it's planned to expand the pro¬
ject until it can produce a beam of
1700MW’. I find this highly unlikely, for
quite a number of reasons.
Unfortunately Tom does not state where
this information came from. There may be a
simpler explanation, as 1700MW would seem
to be about the theoretical isotropic power of
the HAARP transmitter. When discussing
heating and other effects, sometimes the
transmitter power level is quoted as if the
transmitter radiated equally in all directions.
A torch beam compared to a point source of
light illuminating the inside of a globe uni¬
formly would be a visual analogy. The ulti¬
mate HAARP transmitter power of 3.5
megawatts with the antenna gain of about
500 (say 25-30dB) would be equivalent to an
isotropic transmitter of 1700MW. Possibly
the theoretical isotropic power level has been
given in some document and someone has
confused it with the transmitted beam power.
The other claims by Tom in the article
need rather more backup before they could
be seriously considered. I like Tom's writing
style, but he needs to stop writing specula¬
tion as if it was fact. I have always believed
that the more unusual and extreme the claim
the greater the need for evidence. But Tom
does not produce any evidence.
For example he comments on a Russian
transmitter (Woodpecker) that 'many scien¬
tists feel that the woodpecker's real purpose
was to experiment with modifying human
brain function'. Now this is a really major
thing to claim without any supporting
sources. He needs to start naming his
sources if he wants to be taken seriously
rather than comments such as 'other docu¬
ments come from sources we'd rather not
know about ’.
ELECTRONICS Australia, September 1998
31
Forum...
1 hope you find the above comments of
interest.
I did indeed, Mr Cameron, and I imagine
other readers will as well. Thanks for
describing the ionospheric research setup
near Armidale in the early 1970s, and help¬
ing to put the HAARP project into clearer
perspective. Your point that ‘solar wind’ par¬
ticles from the sun can already produce cur¬
rents of millions of amps certainly suggests
that the excitation produced by HAARP is
still rather short of the level needed to
destroy the planet, doesn’t it?
I take your point that our ‘Death Star’
wording in the heading and on the cover was
probably a bit ‘over the top’, but we niche-
market magazines tend to get Tost in the
noise’ nowadays unless we attract attention.
Hopefully the wording did that, at least.
TBC, or synchroniser?
Moving on, our second letter is in response
to the review I did in the April issue, of the
Video Tech VMX400 Video Mixer and
Timebase Corrector. Our correspondent is
Mr Gary Yates, of Frenchs Forest in NSW,
and although he doesn’t say as much I sus¬
pect he’s actually the father of our frequent
contributor Darren Yates. Basically he’s
writing to question the use of the term Time
Base Corrector, by both Video Tech and
myself, in connection with the circuitry in
devices like the VMX400:
Forgive the familiarity, but I feel I know
you. I’ve been reading EA/RTV&H since
1958 and was initiated into electronics via its
excellent articles and construction projects.
I’ve just read the April 98 edition (yes, I’m
a bit behind) and came across your review of
the Video Tech VMX400 vision mixer. From
the article I got the impression this unit is
meant to be used with domestic VCRs. The
following letter is based on this assumption.
Liberally sprinkled through the review are
the capital letters TBC, which of course
stand for Time Base Corrector. I would like
to throw a cat amongst the pigeons and say,
from the description of the device, it is not a
TBC but a Video Synchroniser (VS). These
are two different devices, as follows:
LA VS is a freestanding device and a TBC
is not.
2. A VS requires a 625 TV line memory. A
TBC only needs a 20 TV line memory.
3. A TBC outputs a fault-free video signal,
while a VS does not.
Just to recap, a little bit of tape recorder
theory. Any tape recorder, be it video or
audio, if it is to work well, must maintain its
tape speed accurately. Usually tape
machines have two speed problems:
1. Dynamic speed variation, called Wow &
Flutter ’ on audio tape machines.
2. Static speed offset error, which causes
tone pitch shift on audio machines.
A TBC works to correct these in video
machines as follows.
The usual method to fix dynamic speed
variation on the video output of a VCR is to
feed the VCR output into a memory unit, with
the input, clock locked to the VCR output and
clock it out at a fixed rate locked to a refer¬
ence signal input. The dynamic errors in
most video machines are usually less than
+/-10 TV lines and hence only a 20 TV line
memory is necessary. The output is effective¬
ly tapped halfway down the memory so that
it can increase or decrease the signal delay
by up to 10 TV lines.
As you can probably guess, a small 20 TV
line memory is not going to handle a static
speed error, which will need an ever increas¬
ing or decreasing time delay correction. To
solve this problem a DC control signal is
derived from the 20 TV line memory address¬
ing circuitry, so that:
1. At 10 TV line delay the DC output voltage
is zero.
2. At 20 TV line delay the DC output voltage
is positive.
3. At zero TV line delay the DC output volt¬
age is negative.
The DC output signal swings smoothly
between these limits depending on the aver¬
age time delay. This DC signal is fed back to
the capstan speed servo in the VCR, to speed
up or slow down the tape to remove the stat¬
ic speed offset and keep the average speed of
the VCR video output signal exactly match¬
ing the reference signal fed into the TBC.
There will thus be no time errors on the
video output of the TBC.
Now let's turn to the video synchroniser. A
VS relies on the fact that the video signal vir¬
tually repeats itself every 625 TV lines.
Domestic VCRs do not have any external
inputs to their capstan servo circuitry. Due
to the relaxed tolerances of these servos, it’s
a good bet they will also have a static speed
error to a certain degree and this will get
worse as the VCR ages.
Let us assume that the VCR speed is a lit¬
tle fast (a positive static speed offset) and, at
this point in time, the start of line 1 of the
VCR video output is coincident with the same
point on the reference signal fed to the other
input of the VS.
At the end of line 1 the VCR signal synch
pulse will occur before the synch pulse of the
reference signal. (Because the VCR is run¬
ning fast, the line synch pulse frequency will
be higher and the time between the synch
pulses will be shorter.) The 625 TV line
memory will add a slight delay to the VCR
video signal, to make sure its synch pulse is
coincident with the reference sync pulse.
At the end of line 2 the memory will add a
little more delay again to get both the second
synch pulses to line up, and so on right
through the 625 TV lines in the frame. (Of
course the memory is actually adding tiny
amounts of delay right through each line; not
just one big jump at the end of each line.)
So you can see the memory is adding more
and more delay, until it hits the end stop and
there is no more memory left. The VS over¬
comes this problem by simply snapping back
to zero delay and starting all over again.
This gives an apparent synchronous output,
BUT what actually happened was that the
memory dropped a whole frame of video.
Discarded it. Threw it away. Never to be
seen again. What does this really mean?
Well, if the VCR is running fast, the pic¬
ture will jump forward (skip a frame) every
so often — or if the VCR is running slow, the
picture will jump back (repeat a frame)
every so often. These jumps will give you a
rhythmically jerky picture. Flow often
depends on how far out the speed of your
VCR is. The greater the speed error, the
more often the jerk.
Some advanced video synchronisers get
around this problem by having a Rolling
Frameline Update system. Instead of adding
or skipping one complete frame every 100
frames (for example), they just add or skip
one hundredth of a frame (6.25 TV lines)
every frame. This produces a different fault
on the picture. A scene change can occur
partway down the frame. The previous scene
would be in the top part of the frame and the
next scene would be in the lower part. The
picture update line will cycle through the
frame continuously, but you will only see it
when the scene changes.
A TBC does not produce either of the
above faults and is, in my mind, the better
unit. Unfortunatly, it cannot work with
domestic VCRs.
It would appear that the Video Tech
VMX400 is not a TBC and therefore there is
the chance it will produce picture errors if
your domestic VCR has a static speed error.
Thanks indeed for that explanation and
clarification, Gary. I confess I did half¬
remember the correct terminology and the
distinction between a TBC and a video syn¬
chroniser when I was writing the review, but
used the term ‘TBC’ because Video Tech
and the other manufacturers seem to use it.
I suspect you’re quite correct that the
devices are really video synchronisers, and
would therefore be capable of producing the
kind of picture errors you describe. All I can
say, though, is that during my testing of the
VMX400 — with a couple of different
domestic VCRs, one quite elderly — I really
didn’t notice any errors of this type.
I had assumed that the memory in the
VMX400 was organised like a big FIFO
buffer, where the addressing simply goes
‘around and around’, and both the writing
and reading were on a line-by-line basis so
there wouldn’t be any sudden jumps on the
output. Are you sure they couldn’t be doing
things along these lines?
But that’s about all we have space for this
month. Cheers! ♦>
32
ELECTRONICS Australia, September 1998
Now Books
Cosmic ray saga
COSMIC BULLETS, by Roger Clay and BOiJfcR 11 ay
Bruce Dawson. Published by Allen & & HMUCfl davvson
Unwin, 1997. Soft covers, 198 x 131mm, 194
pages. ISBN 1-86448-204-4. RRP $16.95.
Another title in the Allen & Unwin
‘Frontiers of Science’ series edited by
Professor Paul Davies of the University of
Adelaide, designed to describe current
research and developments in selected topics,
in an accessible way. The authors of this vol¬
ume are also at the Uni of Adelaide, as
research physicists, and are experts in cosmic ray research.
In Cosmic Bullets they explain that despite a fair amount of work
over the last century or so investigating cosmic rays, there’s still a lot
about them that isn’t properly understood — like where many of them
come from, and the exact mechanisms whereby such high energy par¬
ticles are created in the first place. The aim here is to give the reader
a good understanding of what has been achieved to date in studying
these intriguing ultra-high energy particles, what they’ve told us so
far, and what the challenges are for current and future research.
For anyone with a reasonable background in science (which prob¬
ably includes most readers of EA, I imagine), it should make very
interesting and accessible reading. The authors start with a rundown
of basic particle physics, and follow this up with a narrative of what
has been found over the last century. This then gives you a good foun¬
dation to understand and appreciate their description of current
research projects and where they’re heading.
As cosmic ray research is closely allied with electronics, I imagine
many of our readers will find it as interesting as I did. There’s both a
glossary and a bibliography at the end, by the way.
The review copy came from Allen & Unwin, of 9 Atchison Street,
St Leonards 2065. (J.R.)
Learning electronics
TAB ENCYCLOPEDIA FOR
TECHNICIANS AND HOBBY-
ISTS, by Stan Gibilsco. Published
by Tab Books, 1997. Hard cover,
194 x 242mm, 961 pages. ISBN 0-
07-024190-2. RRP $150.
This book is the largest I’ve seen
from this prolific author, which
helps explain its rather high price
tag. It claims to cover virtually every
aspect of hobby and consumer elec¬
tronics, and it certainly covers a lot
of ground. There are some formulae
given, but for the most part things are kept relatively simple. To me,
the book could be improved with more tables, equations and circuits,
and less text.
Being an encyclopedia, all entries are in alphabetical order.
However, there’s also an index which helps you find subtopics with¬
in an entry. The main problem is what it leaves out. The content is
very general, and broadly covers most aspects of electronics, includ¬
ing a few that seem irrelevant. For example, nearly a page is devoted
to the term ‘Luddite’...
As you’d expect, computers and their peripherals get a lot of cov¬
erage, as does radio, television and other consumer appliances. The
book is ideal for browsing, and would certainly give a non-technical
person or a beginner to electronics a good idea of electronic equip¬
ment and appliances. But it is not a reference book for technicians.
The review copy came from McGraw-Hill, PO Box 239, Roseville
2069. (P.P.) ❖
IGBT
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ELECTRONICS Australia, September 1998
33
READER INFO No.13 READER INFO No.12
> • •
Serviceman
The customer who’d imported what was
very nearly an expensive boat anchor!
Paying to have a piece of
very expensive second¬
hand electronics equipment
shipped from the other
side of the world can be
pretty risky — especially
when the equipment
concerned is a high-end
valve hifi amplifier, as one
of this month’s stories
illustrates. We also have
the tale of tracking down
weird intermittent faults in
an ageing germanium-era
electronic organ...
T his month we open the column with a
story from a familiar contributor over
the Tasman, Peter Lankshear. You’ll no
doubt recall that Peter conducted our
Vintage Radio column for many years and
from that you might deduct (correctly) that
he is a ‘full bottle’ on valve technology. This
story continues his association with the old
‘bottles with lights in them’, although this
equipment is more up-market than the old
five-valve mantels he used to write about.
Here’s what Peter has to say...
This story is unusual in that it describes a
repair job that started in England and was
completed 20,000km away, in New Zealand.
It also made me aware of the questionable
ethics of the service persons concerned.
An unforeseen and remarkable develop¬
ment in the ever-changing world of electron¬
ics has been the widespread enthusiasm dis¬
played by a significant number of audiophiles
for perpetuating the use of valve audio ampli¬
fiers. The outcome has been the manufacture
of expensive and technically obsolete equip¬
ment and at times an acceptance of what are,
in fact, reduced performance standards.
A related group of enthusiasts has gone to
great lengths to search out and have refur¬
bished, surviving classic high quality ampli-
Jiers such as the Williamson, Leak and Quad.
Unlike some present day valve counterparts,
these do have high performance figures.
During the 1960s, one of the last of these
classics to appear was the Radford, a 'no
compromise ’ example of the best of valve
technology, with a specification that even by
today’s standards is impressive. Capable of a
genuine 100 watts RMS per channel at 0.1%
distortion , its two output stages each used a
pair of ultralinear connected KT88 tetrodes.
The phase inverter driver stages were
long-tailed pairs of frame grid EF184 TV
pentodes and the input stages used cascode
ECC88 double triodes. The complete stereo
amplifier is quite large, massive and very
heavy. To lift one entails first taking a deep
breath and then risking a hernia!
One local enthusiast was so keen to
obtain one of these monsters that he
arranged the purchase of one in England
and had it air freighted to New Zealand.
What his freight bill totalled, 1 hate to think.
By all accounts, the amplifier had been
used in a pub. That it was working at all is
more a tribute to Radford quality than to its
environment, but the new owner soon dis¬
covered that whilst one channel seemed to
be operating well enough, the other was not.
A new set of very expensive valves did not
help, and it was then that my aid was sought.
/ agreed to look it over and the monster was
duly heaved onto my workbench.
Upended and with the bottom cover plate
removed, some serious modifications were
immediately apparent. The output stage of
the faulty channel had been altered to more
or less straight tetrode operation, with
reduced screen and altered bias voltages.
This suggested that a misguided attempt
had been made to change the operating
conditions to class AB2 — not possible with
conventional driver coupling. This roused
some deep suspicions. It is not unknown for
The Radford STA-25 valve power amp, ‘little brother ’ of the model discussed in Peter
Lankshear's story.
34
ELECTRONICS Australia, September 1998
a circuit to be modified in a vain attempt to
cure a fault, but such desperate measures in
this type of equipment never work.
At this stage, with no data or circuit avail¬
able, I was not prepared to do any more
until some information could be obtained.
The required manual eventually arrived,
and I was able to check all components like¬
ly to have deteriorated, and restore the cir¬
cuit to its original state. Most resistors and
capacitors were mounted on printed circuit
component boards with numerous connec¬
tions to the valve sockets and power supplies.
A methodical progress through the ampli¬
fier revealed only a few components out of
close specification, and most of the work
entailed tidying the wiring, replacing
butchered terminals and sockets and cor¬
recting the modifications. Because I had
found no really faulty capacitors or resis¬
tors, I was had an open mind as to whether
or not the crippled channel would now work.
One hand in pocket...
With the amplifier switched on I took a
detailed set of meter readings and found that
the voltages of both channels were close to
specification. (With 600 volts of HTfloating
around the chassis, I made sure one hand
was firmly in my pocket!) So far so good. It
was now time to listen to the audio quality.
To connect a 100-watt amplifier directly
into a workshop speaker is a bit pointless and
potentially damaging, so I fitted up an 8Q high
wattage load resistor with a small sample of
the output for the speaker. With an FM tuner
connected and the gain wound well up, both
channels produced what seemed to be plenty
of high quality output. Certainly, the horrible
sound from the modified stage had gone. I sat
back, enjoyed the music and speculated as to
the real reason for the modifications.
There was however still a lingering
doubt, so I dusted off the oscilloscope, an
audio oscillator and a meter known to be
accurate at audio frequencies and set about
measuring the output. The good channel
produced a fraction over the required 28.3
volts into 8 ohms, but the other managed
only half of this figure, equal to 25 watts.
This confirmed (a) the futility of using ears
to measure audio levels, and (b) that there
was still a fault.
What was left to go wrong? It had to be the
output transformer. Swapping the connec¬
tions over to the good channel confirmed
that there was indeed one Jaulty transformer.
It was the worst possible fault — and the
most expensive item by far, assuming a spare
could be found, which was unlikely.
Here was the real reason for the modifi¬
cations. Someone had probably discovered
the faulty transformer and had attempted to
correct the lack of output by altering the
output stage. And when this was unsuccess¬
ful, the owner must have decided to quit the
amplifier. I couldn 7 help but wonder if it
would have been exported to New Zealand
had it been in good condition...
A 100W wide range output transformer is
a massive beast. It has about twice the
amount of iron required for a power trans¬
former of the same power rating and is at
least twice the size of the mains transformer
for a large valve receiver. But the real
problem is the very specialised sectional
winding methods. The Radford transformer
has four secondary and four primary wind¬
ings and each primary section is tapped for
the ultra linear screen connections.
Furthermore, two of the primaries are
wound in the reverse direction and as each
pair is connected in parallel, the number of
turns on each section has to be exactly the
same (in this instance WOO turns). If the
transformer could not be repaired or
replaced, there would be an unhappy owner
of a very expensive boat anchor.
Valve amplifier enthusiasts are purists,
and only a Radford transformer would have
really been acceptable.
There was one possible solution. New
Zealand Vintage Radio Society members
are fortunate in that one of their number is
a REAL transformer rewinding expert. He
has been at the game for over 60 years and
will tackle anything, invariably turning out
a superb job with better craftsmanship and
materials than the original.
He also has an extensive database of trans¬
former specifications and when he is con¬
fronted with a new transformer, his first
action is to meticulously unwind it, noting the
exact number of turns and the configuration.
But would he take on the complex Radford? A
phone call ascertained that he would!
The beautifully rewound transformer
duly arrived back and was soon in opera¬
tion with full output now available on both
channels. One very happy owner was able
at long last to enjoy his music, and I was
able to reflect on the perils and expenses of
repairing old amplifiers, and the inadvis¬
ability of importing used equipment.
However, there was one last sting in the
Radford’s tail. A few weeks later the owner
called to say that he now had a small annoy¬
ance. He listened in rapture to the Radford
daily, but about once a week it would briefly
produce a small frying sound that would dis¬
appear as soon as the occupant of one par¬
ticular EF184 socket was touched.
He had tried several new valves to no
avail. A fter all we had gone through, to now
have an intermittent fault was as welcome
as the proverbial hole in the head!
There was nothing for it but to invert the
chassis on the workbench and leave it run¬
ning. Nothing happened for a few days. I
felt it was a dry joint of some sort and even¬
tually resorted to prodding around. Here 1
found that one section of the PC board was
at times microphonic.
Out came the board — again — but a
close inspection with a magnifying glass
showed nothing unusual. I then unsol¬
dered one of the joints in the troublesome
area, to discover that the resistor lead
was quite black under the solder.
This had to be the problem and although
externally they appeared OK, several simi¬
lar joints were found. To make completely
sure I unsoldered all the component leads,
cleaned and then carefully resoldered them.
This was a year ago and the Radford has
not given any further trouble.
If a conclusion can be drawn from this
adventure, it is that all equipment has a
finite life — which can be extended, but
often with considerable and uneconomic
effort. I believe it also shows why it is
unwise to import used equipment without
some safeguards.
So how about that? I wonder what would
have happened if the Transformer Whizz
had been unable or unwilling to tackle the
rewinding job. As you say, Peter, it would
have been a very expensive boat anchor...
Of course, we don’t know the history of
the amplifier. The modifications may have
been authorised by an owner who was quite
satisfied with the compromised perfor¬
mance. I’ve struck people who are happy to
have quite expensive gear patched up rather
than properly repaired.
The argument often is that they aren’t suf¬
ficiently interested in high quality to warrant
the extra cost of full repairs. And I suppose
the attitude is quite legitimate. But then, why
did they go to the expense of buying costly
gear in the first place, if quality wasn’t impor¬
tant? Did they only buy the brand name?
The practice of Tough patching’ only
becomes unethical when the equipment is
sold off and the new owner is not told of the
service history. It’s not often possible to
conduct full output trials on high-end audio
products, and low level tests can be quite
misleading. I imagine that’s what has hap¬
pened in this story.
Thanks for that tale, Peter, and we are
looking forward to your next contribution,
whenever it may be.
RESULT
ELECTRO.\
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E-mail: Hypo@fl.net.au
ELECTRONICS Australia, September 1998
35
READER INFO NO. 14
Serviceman
Hammond organ
And now for a story from another frequent
contributor. He is Robert Abel, from
Condobolin in NSW. This time Robert has
written about a subject that seems to be
much more common these days than in the
past. Here’s what he has to say...
After the last couple of jobs which were
mostly mechanical, this one was a genuine
electronics fault. But after a reel to reel
tape recorder and a VCR, what else could I
get involved with but an electric organ?
The organ in question is a Hammond,
with two 44-key manuals and 13 foot pedals,
and I quote from the service notes: 'The
Upper Manual contains three sixteen-foot
voices, Flute, String and Reed. The Lower
Manual has two 8 ’ stops, Tibia and Cello.
With the addition of Reverb, Manual
Balance, Vibrato I and II, and Pedal Accent,
the VS 100 is a simple but functional organ ’.
Note that VS 100! This particular organ is
a V222, an earlier model with exactly the
same features but using discrete transistors
(germanium 2SB56s), where the VS 100 uses
a simple IC (LD3061) to do the same jobs.
There is a 'Generator ’ board containing
12 oscillators (the top octave) ranging from
554Hz to 1047Hz and these, of course, run
continuously when the organ is switched
on. Other notes are derived from a series of
dividers on three separate boards, con¬
trolled from the key switches on the upper
and lower manuals and the foot pedals. The
various 'voices’ are controlled by rocker
switches alongside the Upper Manual.
I found that the organ had been pur¬
chased as a demo model in 1975, which
also happens to be the year I decided to sit
out my retirement(?) in this town.
I did not become affdiated with the body
which owned the organ until 1977, and it
must have been shortly after that when 1
was persuaded (compulsorily volunteered?)
to restore some key contacts which had
become rather uncertain and scratchy.
Over the years since then, another peculiar
fault developed, manifested at first by an
inability to obtain any output from the firstfoot
pedal (it should sound bass at around 66Hz).
After the organ had been switched on for
a while, brief bursts of bass would erupt
periodically (with the pedal held down)
until eventually the output was continuous
again. And so, for a time the trouble was
not regarded as serious enough to warrant
expert attention.
The 'warm-up ’ periods gradually became
longer over time and then the fifth note on both
manuals became affected, roughly doubling
the pitch when the pedal was inoperative. So it
became the practice to turn on the organ about
4pm, to enable normal use in the evening.
This might have continued indefinitely,
except that this year, with the annual instal¬
REVERB UNIT
PRE-AMP & REVERB
PWB
SWELL PEDAL HOUSING
PEDAL SWITCH ASSY
POWER SUPPLY
MAIN RA. ASSY
Inside a Hammond VS100 electronic organ, showing the main system modules. The
V222 is apparently very similar.
lation looming, the organist reported sever¬
al notes inoperable, necessitating a repeat
of my previous job on the key contacts.
So, there I was, once again cleaning and
adjusting the leaf contacts and allowing my
curiosity to ponder the reason for the bad
behaviour of the first pedal et al.
I took some voltage readings along the
(very dusty) sides of the nearest boardful of
germanium devices (2SB56’s) and found
that the usual result was in the region of
12.5 volts, until suddenly I found a reading
which refused to hold still but seemed to
'toggle ’ between about 5 and 16-19 volts.
This had to be the circuit I was seeking
and to confirm it, after a session with vacu¬
um cleaner and a soft paintbrush, I unsol¬
dered leads variously numbered Ul, LI,
and PI. These were the leads coming from
the faulty notes on the Upper and Lower
manuals, and the first pedal key.
It was not an easy matter to inspect the
underside of the board because of the restraint
imposed by the wiring, but I located a transis¬
tor which had to be part of that circuit and
took it out for testing. It was perfectly OK and
fitting a replacement had no effect at all; the
voltage continued to toggle as before.
That’s when I noticed that there were two
25B56s in this circuit and of course the sec¬
ond one WAS faulty, with very high leakage
current. The toggling effect vanished with
its removal, and after fitting a replacement
a check showed that all three notes were
playing normally again.
I can’t understand why the high leakage
current should cause the device to toggle, but
I assume that the fact of toggling would per¬
haps have racked up a charge on one of the
associated capacitors, sufficiently to stabilise
conditions in the circuit for a time and so pro¬
duce a normal note until the charge dissipated.
But this does not explain why — after an
hour or two — normal operation would
return! No doubt one or more of the organ
service people who read this will put me
right about all this...
I wondered then about the tuning of the
main oscillators and contacted a colleague
who, although older even than myself, still
runs a healthy repair shop and who I knew
had operated on a number of Hammond
organs and could be relied on to have the
necessary information on frequencies, etc.
Armed with my new knowledge and with
trusty 1GHz Counter under arm, I took our
organist over for a trial run. I am quite fond
of music — though totally incapable ofpro¬
ducing any myself — but I wasn ’t sure
whether to be pleased or just a little disap¬
pointed when the expert declared the tuning
perfect and all / needed to do was put the
covers back on! Oh, well, you win some...
That was an interesting interlude, Robert.
As you said earlier, it’s a very electronic yam
and, on reflection, one that has meaning even
outside the field of Hammond organs.
There are still a lot of products about that
use old germanium transistors and your
description of unusual behaviour in those
devices might help to solve problems for
other servicemen.
By an odd coincidence, I was sorting
some old manuals yesterday and came
across a service manual for the Hammond
model VS 100, along with the installation
manuals for a Leslie model 130 speaker and
the 7830 control connector kit. I don’t know
how I came to have them in my collection,
but someone locally must have been work¬
ing on one of these very popular organs.
Thanks for that story, Robert. We’ll look
forward to more unusual tales from your
rather active retirement.
And that’s it for this month. There’ll be
more next time, if the fates are willing. ❖
36
ELECTRONICS Australia, September 1998
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37
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Air speed and
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Pack of 10. Suitable for
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Effective protection against common
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149”
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169“
6-piece precision
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Great for presentations with
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64pc security bit set
Packed in two soft plastic storage cases
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Circuit rfl
Design Ideas
Interesting original circuit ideas and design tips from readers. While this material has been checked
as far as possible for feasibility, the circuits have not been built and tested by us. We therefore
cannot accept responsibility, enter into correspondence or provide any further information.
Break Finder
Simple mod improves Cable
The Cable Break Finder published in
February 1998 is designed to test faulty
cables, but what it can’t tell you is whether
the cable is shorted or OK. This simple
modification will let you test good cables,
and adds an extra level of cable fault find¬
ing to the Break Finder.
A good cable can be tested if one end is
removed from the Break Finder, and a
small capacitor fitted in its place. This is a
bit inconvenient, but a momentary DPDT
pushbutton can disconnect the sockets on
one side, and substitute a InF trimmer
instead. If a balance can be achieved with
the button pressed (and a cable attached to
the other side), then the cable is OK; if not,
then the cable is shorted. To balance the
extra switch capacitance, a trimmer can be
fitted to the other side and be adjusted for
50% balance without any cables inserted.
With this modification, the sequence for
testing a cable would be as follows:
Try to balance for a break in the usual
manner. If this is not achieved, then bal¬
ance for the total cable by unplugging the
cable from the switched side of the tester
and pressing the button.
If a balance still can’t be achieved, then
the cable is most likely shorted and a low-
ohms meter would determine the likely break
point by comparison of both ends.
Note: Cables in the sound industry have
capacitances of around 90pF to shield and
60pF between conductors per metre
length, so a InF (lOOOpF) trimmer could
easily balance cables between 1M and
100M in length.
Victor Erdstein
Highett, Vic. $30
Novel running light display
Running lights or ‘chasers’ are nothing new,
but this one is simple and versatile: The num¬
ber of LEDs in a group can be selected, as can
the number of spaces between them as the
pattern repeats. I used this circuit to create a
pendulum for a mantle clock by using 16
dual-colour LEDs arranged in an arc and with
four shift registers. The pendulum (a group of
three ‘on’ LEDs) swings in green colour from
left to right and back again in red.
The circuit shown consists of two dual shift
registers (IC2 and IC3) and a quad NOR gate.
IC1 a and b are wired as an RS flip-flop. It is set
at switch on via the 0.1 uF capacitor at pin 1,
forcing its output (pin 4) high. Simultaneously
the registers are reset via the lOnF/lOk network
at pins 6 and 14 on both registers. The remain¬
ing gates IClc and d form an oscillator with
variable frequency via the 500k pot.
On the rising edge of each clock pulse, the
data at pin 7 is loaded and shifted from left to
right (CW). The reset pin of IC 1 b connects
to Q2 (the third output of IC2), so when this
goes high it resets the flip-flop, pulling the
data input low. The three LEDs now lit ‘shift
around’ until the last output goes high (Q3 of
IC3 high), which sets the flip-flop again and
the cycle repeats.
The pattern produced resembles a group of
lights chasing around the circle continuous¬
ly. The circuit can be expanded by adding
one or more shift registers in series, where
one of the last outputs of the chain is con¬
nected back to the ‘set’ input of the FF.
Programming is easy, for example:
required string of 20 LEDs and group of five
LEDs chasing, solution: three series-con¬
nected shift registers are needed, the reset
line connects to the fifth output in the chain,
the fourth output (the twentieth in the chain)
of the third register connects back to the ‘set’
input of the flip-flop.
Manfred Schmidt
Edgewater, WA $30
42
ELECTRONICS Australia, September 1998
As an added incentive for readers to contribute interesting ideas to this column, the idea we
judge most interesting each month now wins its contributor an exciting prize, in addition to
the usual fee. The prize is a complete closed circuit TV system, comprising a 5” B&W video
monitor, CCD video camera with stand, power supply and cabling. This system comes from
our sponsor Allthings Sales & Services, and is valued at $369.00!
Universal IR Controller
for a PC
This simple circuit allows you to record any IR
remote control signal on your PC, and then play
it back. This is particularly useful if you want to
control appliances such as TVs, VCRs, CD
players etc., from your computer. The device
simply connects to the parallel port of your PC,
and you can also use this circuit to analyze the
waveform from any IR remote control.
The circuit consists of two parts. The first part
is the IR receiver, made up with an OP-505 IR
photo transistor. This signal is buffered and
squared up by the Schmitt trigger inverters
(74HC14). The output of the second inverter
goes directly to the Acknowledge line (pin 10)
of the parallel port. The software polls this
line in the recording mode and stores the
incoming data sequence.
The transmitter consists of a clock generator
(555) set to run at 80kHz, connected to a
74LS74 D-type flip-flop. The flip-flop divides
the clock signal by two, giving a precise 50-50
duty cycle on a 40kHz signal. This is then used
as a carrier for the transmitter section of the
circuit. In playback mode the software turns
the DO line of the parallel port on and off at the
same rate that it recorded the signal, which is
used as a gate signal for the 40kHz carrier. The
gate action is achieved by controlling the reset
input of the D flip-flop. If the reset line is low,
Low current bar-graph display
then the Q output is also held low.
This gated signal is then used to drive the IR
LED via the driver section. The IR LED driver
section consists of a 7405 hex open-collector
buffer. All the outputs of the 7405 are tied
together to give enough current to drive the IR
LED. The two 1N4001 diodes are used to step
down the voltage to around 3V for the IR
LED. This may seem to be a bit of overkill, but
it does mean that you can drive several IR
LED’s simultaneously. The 555’s frequency
can be adjusted for remote controls whose car¬
rier frequency varies from the standard 40kHz.
This bar-graph display achieves low current con¬
sumption by switching the LEDs in series, as
opposed to the conventional parallel arrangement.
Resistors R3 to R8 set the threshold voltages
in 2V increments, from 2 to 10 volts. These
resistors can obviously be changed in value to
suit the desired application. As the input value
exceeds 2V, Ul’s output swings low, turning
on the constant current source based around
Ql. Because the outputs of U2 to U5 are still
low at this point, only LED1 will light.
As the input voltage increases from 4V to
12V, U2 to U5 will switch on consecutively,
allowing current to flow through LED2 to
LED5 respectively. Due to the constant current
source, only 10mA will flow through the LEDs
whether only one is on, or all of them are on.
If the input voltage is below the minimum
threshold, U1 will switch to + 12V, turning
off LED1. The total current consumption is
around 13mA when the LEDs are on, other¬
wise it falls to almost zero.
Wayne Robjent
Tuart Hill, WA $30
The record/playback software can be obtained
free of charge from http://www.geocities.
com/SiliconValley/Lakes/7156, and it allows
you to record/playback and view just about any
IR remote control signal. The real fun begins
when you write your own software to control
your house. For example, a program can be
easily written that automatically programs the
clock on your VCR, TV and anything else.
George Katz
Manly Vale, NSW $40 ♦>
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ELECTRONICS Australia, September 1998
43
READER INFO N0.17
Construction Project
‘Front End 9 for
PC Audio Recording
Like to try using your PC for CD-quality digital audio recording? Or for making your
own CD copies of treasured old analog recordings? Most modern PCs and their sound
cards are capable of doing things like this, but the job will be a lot easier if you build
and use this handy ‘recording front end’. It provides stereo preamps for a magnetic
pickup and microphone, combined with basic mixing and tone control facilities.
by Jim Rowe
It’s a bit of a squeeze , but with care everything fits into one of the small sloping-front
instrument cases.
O nly a few years ago, the equipment
needed for high quality digital audio
recording seemed way out of reach for
most of us. High quality professional analog
to digital converters had equally ‘profession¬
al’ price tags, and only dedicated profession¬
als could justify the cost of hard disk drives
with the many hundreds of megabytes of
storage needed — because with CD-quality
stereo, you need over 10MB per minute.
As for recording your own CDs, that
seemed even more in the realm of fantasy...
Happily, though, that’s all changed. Most
modem PCs are fitted with sound cards
whose A/D converters are capable of sur¬
prisingly good quality, and with hard disks
of multi-gigabyte capacity. Even with the
steadily expanding size of modem software
(‘bloatware’), there’s still likely to be
enough space to store the tracks for at least
one CD’s worth of audio...
When it comes to CD recording, you can
also get CD-R ‘burner’ drives which are capa¬
ble of recording very acceptable (and fully
compatible) DIY audio CDs, plus a variety of
easy-to-use software to help you perform
audio recording to hard disk, edit your digital
audio files and then write them to a CD. So
now, almost anyone with a reasonably mod¬
em PC can use it as the basis for a high qual¬
ity digital audio recording system — and for a
lower outlay than you probably expect.
One very attractive use for such a system
is for making personal CD copies of old and
treasured analog recordings — from old
shellac ‘home recording’ discs, or old
78/45/33.3rpm commercial pressings, or
even old reel-to-reel magnetic tapes. As part
of the copying process you can often take the
opportunity to ‘clean up’ the old recordings,
by removing irritating imperfections such as
surface noise and crackle. There are now
some excellent programs available to do this,
like DART Pro 32 and Diamond Cut.
If you’ve tried doing any of this copying,
though, you’ve probably found that there’s
more to it than simply hooking up your old
analog turntable or tape recorder to your
PC’s sound card. Things are never that easy,
are they?
For example most hifi turntables were fit¬
ted with a magnetic cartridge, which needs
to be fed through a preamp with the correct
RIAA equalisation in order to produce ‘flat’
signal levels suitable for feeding a sound
card. And even though the signals from your
tape recorder or deck might be adequate in
level, you might want to do a spot of pre¬
equalisation — perhaps to boost the bass a
little, or reduce the level of tape hiss, or cor¬
rect other deficiencies in the original record¬
ing. (It’s generally not a good idea to rely
wholly on the software DSP facilities to
bring the signals ‘up to scratch’...)
You might also want to be able to hook up
a microphone, to add some narration or a
spoken introduction to the recordings you’re
transcribing. Most sound cards do have a
mic input jack, but this is usually not easy to
access, and it’s often simply disabled when
the line inputs are used. Generally it’s much
more convenient to have an external mic pre¬
amp and mixing setup. (The performance
can also be significantly better, because the
response of the mic preamp in many sound
cards is quite poor.)
In short, there’s really a need for a flexible
‘recording front end’ unit, to interface between
the PC’s sound card and these audio signal
sources, and provide gain and equalisation.
Needless to say that’s the very purpose of the
handy little unit described in this article.
44
ELECTRONICS Australia, September 1998
ELECTRONICS Australia, September 1998
45
o iuf 12V plug pack or battery supply.
Construction Project
Front End for PC Audio Recording
Here’s the overlay diagram for the PC board. There are only three wire links — one
either side of U4, at upper right, and the third just above U5 and below C42.
What it does
Basically the unit consists of four circuit sec¬
tions: a stereo magnetic pickup preamp, with
the appropriate gain and RIAA equalisation
for ‘conditioning’ the signals from a magnet¬
ic pickup; a stereo mic preamp, with suffi¬
cient gain to operate with most common
dynamic or electret microphones; a simple
two-input stereo mixer, to allow control of the
signals from the mic preamp and either the
magnetic pickup preamp, or a Tape/Line level
stereo input; and finally an active tone control
circuit with bass and treble controls, each
capable of around 12dB of either boost or cut.
It all fits in a compact sloping-front utility
box, and operates from a low cost nominal
12V DC plug pack supply (or a 12V battery
supply, if you prefer).
With the unit, your PC and its sound card
are provided with all of the basic facilities
for convenient digital audio recording.
By the way, the facilities it provides real¬
ly aren’t restricted to use with a PC sound
card. You could also use it as a very basic
‘recording console’ for commercial audio
CD recorders and DAT recorders...
How it works
Each of the four functional circuit sections is
based on an LM833 low noise dual op-amp,
as you can see. The mic preamps use U1, the
magnetic pickup preamps
U2, the mixer stages U3
and the tone control stages
U4. We’ll now look at
these briefly in turn.
The mic preamp stages
(Ula/b) are quite conven¬
tional, with negative feed¬
back used to determine
the voltage gain. Switch
SW2a/b allows the gain of
each stage to be set to
either ‘High’ or ‘Low’,
corresponding to a total
gain of around 1050 or
300 respectively (60dB or
50dB), to suit either low
output or higher output
microphones. The fre¬
quency response of the
mic preamps is essentially flat, within 2dB
from 35Hz to 18kHz.
The magnetic pickup preamps (U2a/b) are
also quite standard, using a well-proven con¬
figuration and circuit values as used in Rob
Evans’ recent Playmaster Pro Series Control
Unit No.4. The feedback circuitry (R12-15,
Cl2-14 etc.) gives a very close approxima¬
tion of the correct RIAA equalisation char¬
acteristic, to ensure a clean and balanced
output from the majority of magnetic car¬
tridges (moving magnet type). The preamp
gain is around 35dB at 1kHz.
As you can see the output of the magnetic
pickup preamps is taken to switch SWla/b,
which allows you to select either the magnet¬
ic pickup signals or those at the Tape/Line
level inputs, as your inputs for the ‘PU/Tape’
channel of the mixer — controlled by ganged
volume pots RVla/b. The outputs from the
mic preamps are taken directly to the ‘Mic’
channel volume pots RV2a/b.
The mixing stages (U3a/b) are again very
conventional, with resistors R25-27 and
R28-30 used to achieve low interaction ‘vir¬
tual earth’ mixing of the two input channels.
With the resistor values shown the maxi¬
mum mixer gain is two (6dB), and this
becomes the ‘flat’ gain of the complete cir¬
cuit for signals fed into the Tape/Line inputs.
The tone control stages (U4a/b) are also
quite standard, using the time-honoured
Baxandall feedback circuit. This provides
bass and treble controls, each with the abili¬
ty to achieve up to about 12dB of boost or
cut (at 50Hz and 15kHz respectively), and
with very little interaction. In the ‘flat’ posi¬
tions of the controls the overall response is
within ldB from below 30Hz to around
25kHz — significantly better than most
sound cards themselves.
The mixing and tone control circuitry has
the ability to provide over 6Vp-p output before
clipping, into the line input circuitry of a typi¬
cal PC sound card (roughly 40 - 50k£2in par¬
allel with about InF). This means that at the
2Vp-p maximum input level needed by the
Line inputs of most sound cards, the distortion
is quite low — typically less than 0.05%.
The op-amps in all four signal processing
sections of the unit operate
from regulated +/-5.5V sup¬
ply rails. These are derived
from the nominal 12V DC
input by a simple on-board
power supply circuit.
Regulator U5 provides the
+5.5V rail directly, while
the negative rail is generat¬
ed by a simple polarity-
inverting circuit which uses
555 timer U6 as a self-oscil¬
lating power chopper, dri¬
ving C40/41 and D2/3 as a
charge-pump rectifier dri¬
ving negative regulator U7.
With a nominal 12V DC
input the negative voltage
generated across C41 is
around 9.5V under load,
giving plenty of ‘headroom’ for U7.
Note that in this project the inverting chop¬
per U6 is intentionally operated at around
70kHz, to minimise the possibility of interfer¬
ence with either the audio signals themselves
or the sampling clock of the PC sound card.
As you can see both U5 and U7 have
1N914 (or similar) diodes in series with their
common lead, to increase their outputs by
about 0.5V. This has been done to allow for
the voltage drops in decoupling chokes L3
and L4, ensuring that preamp chips U1 and
U2 still receive more than the minimum
An audio preamp/mixer/tone control unit to facilitate digital audio recording with
a PC and sound card.
Magnetic Pickup Preamps: Low noise, provide full RIAA equalisation for use
with moving-magnet cartridges. Provide approximately 35dB gain at 1kHz (total
effective gain 41 dB). Input impedance 50k.
Microphone Preamps: Low noise, provide selectable total effective gain of
either 1050 (60dB) or 300 (50dB) to suit mic output. Response flat within 2dB
from 35Hz to 18kHz. Input impedance 100k.
Mixer: Basic two-channel active stereo mixer, able to control levels from Mic
and Pickup-Tape/Line inputs independently. Tape/Line input sensitivity 350mV
RMS for 2Vp-p output at 1kHz; input impedance 50k.
Tone Controls: Active Baxandall type, with independent bass and treble
controls providing up to 12dB boost or cut at 50Hz and 15kHz. The ‘centred
controls’ response of mixer and tone control stages is flat within IdB between
20Hz and 20kHz, with in-band noise around -70dB below 2Vp-p output.
Power Source: 11 - 15V DC, from external plug pack supply or battery.
Current drain approximately 95mA, power consumption 1.2 watts.
46
ELECTRONICS Australia, September 1998
m out
I R
Use the inside view above as a guide when
you're wiring up your own unit. Note,
however, that the wiring to the tone controls
and mic volume pots should be dressed so
that it is kept as far away from the power
supply chopper circuitry (i.e., U6, C40-41 etc)
as possible, when the case is closed. This
minimises pickup of the 70kHz switching
signal. Note also that this prototype uses an
earlier version of the PCB, which had no
provision for on-board mounting of output
series resistors R51-52 — that’s why they're
visible ‘hanging off the output terminal pins.
At right is a rear view of the assembled unit.
TAPt/lINT IN MIC MAG. PICKUP IN
L R l R
•) Q m (# 0
mL _rr—.. . .
ELECTRONICS Australia, September 1998
47
‘Front End’ for PC Audio Recording
Construction Project
At left is the PCB etching
pattern for the project ,
while at right on the facing
page are the patterns for
the front and rear panels.
All are shown actual size
so they can be used for
making your own if you
wish. Photocopies can
also be used as templates
for drilling the holes in
your case.
allowable voltage (+/-5V).
By the way, the schematic shows the pro¬
ject’s allowable DC input voltage range as 11-
15V. At the top end this allows a comfortable
margin for the 555 chip (U6), which has a
maximum voltage rating of 18V. If you do use
a plug-pack supply with a nominal DC output
of higher than 12V, make sure it doesn’t rise
above 18V under light loading conditions.
Construction
The unit is housed in a small sloping-front
utility case, with most of the components
mounted on a PC board measuring 139 x
70mm, and coded 98rfe9. The PCB mounts
horizontally in the bottom of the case, with
the controls mounted on the sloping front
panel. The input and output connectors are
mounted along the rear of the case.
The case used for the prototype measures
190 x 120 x 65/36mm, but other similar cases
may be compatible — the main thing to watch
is the minimum internal height, to ensure clear¬
ance between the components on the PCB and
those on the front panel. Things are fairly tight,
especially just below the two mixer pots.
Because the case is predominantly plastic,
and provides very little shielding, a small
‘shield plate’ cut from unetched PCB lami¬
nate is mounted under the main PCB, with its
copper layer connected to signal earth. The
metal front panel and the controls mounted
on it are also earthed, for the same reason.
The overlay diagram and internal photos
should give you a good idea of where every¬
thing goes, and its orientation. I suggest that
you begin construction by fitting all of the
smaller components to the PCB, using the
overlay and schematic as a guide.
It’s easiest if you begin by fitting the PCB
terminal pins first; there are 42 of these,
used for all of the off-board connections.
Then fit the three wire links and all of the
resistors, as they’re all mounted horizontal¬
ly and have a low profile. You can follow
these with the three power diodes D1 - 3 and
signal diodes D4-5, making sure that they’re
all orientated correctly.
If you’re going to use DIL sockets for the
five ICs, these could now be fitted. (It’s up to
you whether sockets are used, as the argu¬
ments for and against are closely balanced.
Sockets will allow convenient replacement of
chips in the future, but are also in themselves
a significant source of unreliability. They
were only used in the prototype unit pictured
to allow testing of different chips during
development of the project. If I were building
up another unit myself, I’d forget the sockets
and fit the ICs directly to the board...)
PARTS LIST
Resistors
Capacitors
All 0.25W, 1%
metal film unless specified:
Cl,4,5,7,
Rl,5,27,30
100k
15,22,33,34
0.47uF MKT
R2,6
180 ohms
C2,6,9,16
47uF 3VW TAG tantalum
R3,7,35,36,
C3,8,23,
37,42,43,44
27k
27,35,36
O.luF monolithic
R4,8,ll,19
68k
CIO,17
lOOpF ceramic
R9,17
150 ohms
C11.18
2.2uF 16VW TAG tantalum
R10,18
180k
C12.19
220uF 10VW RB electrolytic
R12,20
82 ohms
C28,32
220pF ceramic
R13,21
3.9k
C13.20
18nF MKT
R14,22
39 ohms
C14.21
68nF MKT
R15,23,25,
C24,29,39
lOnF MKT
26,28,29
47k
C25,26,
R16,24,41,48
470k
30,31
4.7nF MKT
R31,32
22k
C37
lOOOuF 16VW RB electrolytic
R38,39,45,46
4.7k
C38
3.3nF MKT
R49
2.7k
C40,41
220uF 16VW RB electrolytic
R50,51,52
470 ohms
C42,44
lOOuF 10VW RB electrolytic
RV1,2
Dual 50k log pot
Semiconductors
RV3
Dual 100k linear pot,
Ul,2,3,4
LM833
centre indent
U5
7805 +5V regulator
RV4
Dual 25k linear pot,
U6
LM555 timer
centre indent
U7 7905 -5V regulator
Dl,2,3 1N4001 power diode
D4,5 1N914 (or 1N4148) diode
Miscellaneous
L1.L2 8T 0.25mm ECU on
F29 ferrite bead
L3,L4 ImH RF choke
SW1,2 Miniature toggle switch, DPDT
LED1 3mm red LED
Sloping-front case, 190 x 120 x 65/36mm or
similar; PCB, 139 x 70mm, code 98rfe9; piece
of unetched PCB laminate, 139 x 70mm, for
shield plate; 42 PCB terminal pins; five 8-pin DIL
sockets (optional); front panel dress plate, 175 x
100mm; rear panel dress plate, 175 x 25mm;
six RCA sockets, panel mount; 3.5mm stereo
jack socket, panel mount; 2.1mm or 2.5mm
concentric power input socket, panel mount; one
screw terminal, black; shielded audio cable,
rainbow ribbon cable for off-board connections;
four 12mm x 3mm dia machine screws,
countersink head, with eight matching nuts and
star lockwashers; solder, etc.
48
ELECTRONICS Australia, September 1998
Next you can fit the smaller ceramic and
MKT capacitors, followed by the larger
MKTs, TAG tantalums and aluminium elec-
trolytics. (Take care with the orientation of
the latter parts, as they’re polarised.) Then
you can fit the two decoupling chokes L3
and L4, and wind the two small RF suppres¬
sor inductors LI and L2 — each of which is
made from eight turns of 0.25mm enamelled
copper wire on a single-hole ‘bead’ of F29
high-frequency ferrite.
With the passive parts all fitted to the
board, I suggest that you next fit only the
three power supply ICs: inverting chopper
U6 and regulators U5 and U7. The latter
both mount horizontally, with a 9mm x 3mm
diameter machine screw and nut to attach
them securely to the board and provide
minor additional heatsinking.
With these fitted, and before you fit the
four op-amp chips, you can connect up the
board to the plug pack supply or another
convenient source of 12V DC, and make
sure the power supply section is working as
it should. This will help avoid possible dam¬
age due to wiring errors.
With the 12V source connected, a DMM
should be able to measure +5.5V at the out¬
put pin of U5 (the pin nearest C27), and -
5.5V at the output pin of U7 (the pin nearest
C43). Similarly you should find about
+ 11.5V at pin 8 of U6, and around -9.5V at
the anode of D3 (the end furthest from R49,
towards the end of the PCB).
If these voltages all check out correctly,
you can switch off the supply and confident¬
ly proceed with the assembly by fitting the
four op-amp ICs (Ul-4). Your completed
board assembly can then be placed aside
while you prepare the case.
A photocopy of the front panel artwork can
be used as a template for drilling and reaming
the holes in the panel for the pots, switches
and LED. I suggest you use the actual con¬
trols as a guide to the final holes sizes, as
bush sizes can vary significantly. You might
also want to drill ‘blind’ holes from the rear
of the panel, to accept the locating spigots for
the pots and switches; this prevents them
from rotating later, without the need for
excessive tightening of the mounting nuts.
If you’re using a dress panel based on our
front panel artwork, this can be applied care¬
fully after the panel is prepared, and the
holes cut out with a hobby knife using those
in the main panel as a guide.
With the panel now prepared, I suggest
that you fit the LED into its close-fitting
3mm hole, and cement it in place with a dob
of epoxy glue or similar at the rear. The
panel can then be placed aside for a while, to
allow the glue to set.
The holes for the rear connectors can be
drilled and reamed next, using the connector
ID label artwork as a guide. Most of the con¬
nectors are single-hole RCA sockets, which
need a hole 6mm in diameter. This is also the
hole size needed for the 3.5mm mic jack.
The size of the holes for the power connec¬
tor and turntable earthing terminal will
depend on these components themselves.
The only remaining holes are those for
mounting the PCB assembly in the bottom
of the case. These are 3mm in diameter, and
can be marked out using a photocopy of the
PCB artwork as a template. If you’re using
countersink-head screws as I did, you’ll
need to countersink the holes on the outside
of the case to suit.
If your 139 x 70mm rectangle of unetched
copper (for the shield plate) is not already
drilled, you can use the PCB artwork copy as
(Continue J on page 73)
ELECTRONICS Australia, September 1998 49
15 — Designer door alert
This twin-tone door alert is
not intended to be a
raucous alarm to wake the
whole family. Instead, it
produces a well-bred signal
that someone is waiting
patiently (we hope!) for you
to answer the door. It can,
of course , be used
anywhere you want a more
friendly tone , such as a
shop doorway alarm where
you don’t want to scare off
the customer...
T his project is called a ‘Designer’ alert
because you can tailor the sound to suit
your own preferences, simply by making
a few modifications to the circuit connec¬
tions. (I’ll go into more details on this later.)
Pressing a switch activates the alert and,
since this is a fairly simple and inexpensive
circuit to build, the price of a real front
door push-button is included in the ten dol¬
lars — but any kind of switch will operate
it. For example, it could be used in a shop
to warn you that a customer is waiting, with
a micro-switch attached to the shop door.
Or you could fix a suitable switch to the
front gate to inform you that visitors are
imminent. Athough its basic sound is rea¬
sonably genteel (but insistent enough to be
+6V o - o o --
SI
easily heard), you can, if you want, pro¬
gram it so give a much more demanding
‘Hurry-up-l’m waiting’ clamour.
How it works
The sounds are generated by an oscillator
included in IC1 (Fig. 1), which also contains
a 14-stage binary divider. The frequency of
the sound is determined by the values of Cl
and R2, where f= 1/(2.2RC).
With the values given in Fig. 1 the clock
frequency is almost exactly 20kHz. This
goes through four stages of binary division
before we see it again at pin 7. Four binary
stages are equal to division by 16, so the
signal at pin 7 has a frequency of 1.25kHz.
This is comfortably within the audio range
and makes a suitable basic frequency for the
rest of the circuit’s operation.
To obtain a two-tone signal we require a
second frequency, which we pick up from
further along the divider chain. In the cir¬
cuit we are showing here we are using the
output from stage six, which is one quarter
the frequency of stage four — in other
words just over 300Hz.
Further still along the chain, the frequen¬
cies drop below the audio range. For exam¬
ple at stage 13 the frequency is 20kHz/2 13 =
2.44Hz. This is inaudible (except as distinct
‘clicks’), but is useful enough for control¬
ling the two-tone effect. We’ll refer to it as
the control signal.
The two audio signals from pins 7 and 4
Table 1: Frequencies available from IC1
(relative to the basic frequency at pin 7)
Pin
Relative freq.
7
1
) Suitable
5
1/2
) for
4
1/4
) audio
6
1/8
) signals
14
1/16
13
1/32
15
1/64
) Suitable
1
1/256
) for
2
1/512
) control
3
1/1024
) signals
Fig.1: The heart of the circuit is IC1, which combines a ‘clock ' oscillator with a 14-stage
binary counter. We use selected outputs from IC1 to both make the audio tones and
control them, via IC2.
*
50
ELECTRONICS Australia, September 1998
by Owen Bishop
Fig.2: Here’s the
wiring diagram
for the door
alert, as built on
a piece of
stripboard.
23456789 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
are taken to a pair of NOR gates in IC2
(gates a and c). Each of these also receives
a version of the control signal. Gate a
receives it directly, while gate c receives it
after it has been inverted by gate d. Gate d
has its two inputs wired together so it oper¬
ates as an inverter (or NOT) gate.
When the control signal is low, gate a
passes the 1.25kHz signal and (since the
inverted control signal is high) the output of
gate c is held low. On the other hand when
the control signal is high, the 300Hz signal
passes gate c and the output of a is low. The
outputs of a and c are fed to gate b which
acts as a mixer.
In this way transistor Q1 receives the two
audio signals alternately. The transistor
switches current through the loudspeaker
and we hear a two-tone sound.
Design options
For anyone with time to spare, there is quite
a lot of scope for playing around with the
values and connections in this circuit, and a
varied range of effects is possible. Here are
some pointers to get you started:
• The basic tone is set by the frequency of
the oscillator. Set this by choosing suit¬
able values for R2 and Cl, remembering
that the frequency is divided by 16.
Having done this, make the value of R1
around 10 times R2. If you want a really
high tone, you can take the signal direct
from pin 9. Just remember that you
might not hear it if the oscillator is
working above 15kHz and your ears are
not as young as they were! If so, try
increasing Cl a bit.
• The frequency of the alternate tone is
derived by tapping the divider chain at
different points. We have tapped stage six
to get a 4-to-1 frequency ratio. Other tap¬
pings produce quite different sounds and
Table 1 shows what is available.
• The rate of tone change is decided by
where the control tap is placed. Generally
stages 10 to 14 are the most suitable, but
interesting warbling effects are produced
by using one of the earlier stages.
• There is no volume control in this circuit.
Volume is plentiful with R3 as shown,
but you could increase R3 to produce a
softer tone.
Construction
The circuit is intended to operate on 6V,
either from a 6V mains plugpack (non-regu-
lated) or a battery pack of four AA cells.
Since it takes current only when the button is
pressed, the batteries should last you a long
time. The project is best housed in a small
plastic box, with an aperture cut for the
speaker. We used a 40mm Mylar miniature
speaker, which is easily glued to the panel by
its rim. Firm mounting is essential if you
want maximum sound volume.
If you want to experiment with the con¬
nections, it is best to wire up the circuit on
a breadboard, and start tinkering! There’s
lots of room on the stripboard to make
changes to the circuit if you change your
mind later on.
Assemble the circuit on stripboard (Fig.2)
noting that the strips are cut in some places
beneath the board, but NOT at C10 and F10.
Solder blobs can be used to join adjacent
strips at certain places, including pins 12
and 13 of IC2. You may decide to alter
some of the connections between the ICs
(the orange wires in the photo) either now
or later. ❖
Parts List
Resistors
Carbon or metal film 5 %, 0.25 W
R1 47k
R2 4.7k
R3 2.2k
Capacitors
Cl 4.7nF MKT or greencap
Semiconductors
IC1 4060 14-stage counter/divider
with oscillator
IC2 4001 quad 2-input NOR gate
Q1 BC338 NPN transistor
Miscellaneous
SW1 N/0 pushbutton switch
LSI Miniature loudspeaker, 8Q, 1/4W;
Matrix board 17 x 39mm (10 strips x 26
holes); 3 x 1mm terminal pins; 14-pin 1C
socket; 16-pin 1C socket; wire for linking
push-button to circuit.
THE TIGER COMES
TO AUSTRALIA
You’ve seen the BASIC Tiger and Tiny Tiger
advertised in the US magazines: they are
now available in Australia from JED.
Tigers are modules running true complied (not
tokenised), Multitasking BASIC at 20 Mhz, but only
draw 45mA. They have memory, 4 x 10-bit analog
inputs, digital 1/0, two serial ports, RTC, and are
superb small controllers for scientific and
industrial applications. A Tiger with 128kB
FLASH, 128kB CMOS RAM and RT clock costs
only $162.A development system (W95), with a
proto board, is only $275. JED has a local
board/controller with LCD/Kbd and industrial 1/0.
See our www site or call for data sheets.
Three PC/104 single board computers
based on
X86, one
with
5 UARTs,
LPT &
! JBUS.
The PC540 (at $350) uses an 80C188EB, with 40
1/0,2 UARTs & timers uses $179 Pacific C.
The PC541 is a V51 PC/XT DOS computer with 20
1/0, PC UARTs, LPT, FDC IDE disk. The new PC543
uses an AMD ELAN (386) cpu at 33 Mhz with 4 MB
DRAM, 16 MB FLASH, five RS232 (2 opt. RS485),
LPT and JBUS. (All have JBUS, JED’s 26-pin ribbon
cable bus for industrial 1/0. All boards are
3.6” by 3.8”on the PC/104 bus, and range from
$350 to $500.)
$300 PC-PROM Programmer
Also: $145 Eraser with timer.
This programmer plugs into a PC printer port and
reads, writes and edits any 28 - pin or 32 pin PROM
without needing special plug-in cards.
JED Microprocessors Pty Ltd
www.jedmicro.com.au
173 Boronia Road, Boronia, 3155
Ph 03 9762 3588
Fax 03 9762 5499
(prices do not include freight or sales tax.]
ELECTRONICS Australia, September 1998
51
READER INFO NO.18
—
1 AH AA NICAD BARGAINS
N
DETECTOR
A quality tool that
STOCK UP AT THE
Standard Typem^
Normally $4.75ea
September
$3.75ea or
10 for $30
Cat. SB-2440
• E PRICES!!
Solder Tags
Normally $4.95ea
September
$3.95ea or
10 for $32
Cat. SB-2441
LIGHTWEIGHT
DIGITAL PHONES
Digital quality sound with fully
adjustable headband and soft leather
padded ear cups. Gold plated 3.5mm
stereo plug with adaptor for 6.5mm.
Frequency 18Hz to 22kHz.
Only $19.95 Cat. AA-2006
rm
DIGITAL HEADPHONES
GIFT
VOUCHER
aycar
VOUCHER
will find wooden
studs, metal,
nails, screws and
voltage. When anything
is detected, a LED will
light up next to the
corresponding symbol -
and a buzzer will sound.
Includes a 2 way switch,
one position for studs,
the other for metal and
voltage. Also has a low
battery warning. Uses a
9V battery not supplied.
Size 175x38x23mm. Cat. QP-2280
Only $29.95
SEMICONDUCTOR
PACK
Brand new batch.
Contains a minimum of
100 pieces. Packs may
include transistors, ICs,
diodes, and there may
even be a bonus in
there!! We do know that
at $10, it represents an absolute
bargain! Note Picture is a
representation only. C+j|| Ollly
Cat. ZP-8990 $ 1 ()
NEW CELLULAR
NOKIA 1610
Ni-Mh 1200mAh.
Standby 100 hours.
Talktime 360 mins.
PINHOLE CCD
Hides behind a
pinhole! Includes
BNC & power
socket. For
specs, see
QC-3470 on
200, in
our 98 Cat.
Cat. QC-3471
NOKIA 6110
Ni-Mh 950mAh.
Standby 80 hours.
Talktime 280 mins.
149.50
Cat. SB-2552
$59.50
Cat. SB-2554
ERICSSON 788
Ni-Mh 600mAh.
Standby 30 hours.
Talktime 90 mins.
$49.50
Cat. SB-2577
JAPANESE CELLS, ASSEMBLED IN TAIWAN $49.50
NOKIA 3110/3810
Ni-Mh 1200mAh. Standby 120 hours.
Talktime 280 mins. Cat. SB-2553
$49.50
ERICSSON 628/688
Ni-Mh 1200mAh. Standby 100 hours.
Talktime 360 mins. Cat. SB-2576
$49.50
NEC FIDO
Made by YOGA, the company that
makes all our microphones! These
feature *High compliance 50mm
diaphragm »High performance cobalt
magnet ‘Single side cable entry *ln line
volume control ‘Gold plated 3.5mm
stereo plug with adaptor for 6.5mm
•Frequency 18Hz to 22kHz.
Only $44.95 Cat. AA-2008
POWERTECH
12 V, 15 V, 18V
DC 800MA
REGULATED
SWITCHED POWER SUPPLY
Has switchable voltage and polarity. Output lead is 4
way moulded star plug which has 2.5mm & 3.5mm
plugs & 2.1 mm and 2.5mm DC plugs and a 1.3mm DC plug.
Cat. MP-3034
Ni-Mh 1200mAh. Standby 60 hours.
Talktime 180 mins. Cat. SB-2582
12V 150W /%
NEW ADAPTOR
VI.
D9 Female to RJ45 Female.
Cat. PA-0906 $5.95
DE-SOLDER BRAID
Cat. NS-3020
WAS $2.95 {
$1.50
!TI1#E #
CD-R BARGAINS
RICOH
COLD
Cat. XC-4710
•Rll
Now in 4
colours. Ideal
for house,
shop, display
and garden lighting.
Large size - 51 mm dia.
38° wide angle.
50 watt.
RED SL-2741
GREEN SL-2742
BLUE SL-2743
YELLOW SL-2744
JIMP MODULI
Will deliver 150W
RMS into 412 and
100W RMS into
812. Make your
own active
subwoofer. See
98 Cat. page 57
for details.
Cat. AA-0500
o
SLACK DISK
Pkt. 25 Pkt. lO
was was
$15.95 $5.95
NOW NOW
$11.95 $4.95
Save $2 Save $1
XC-4740 XC-4739
COLOURE disks
Pkt 25
Was $14.95
NOW $12.95
Save $2
Cat. XC-4742
91# AC 1 AMP
Grab some of these while you can.
Surplus stock purchase of 240V AC
adaptor plugpacks to 9V AC at 1
AMP. Terminated to a 2.5mm DC plug. Cat. MP-3024
Normally
septi
Buy 10 $8ea. Buy 50 $7ea.
(3CSX7 [&D®g)®t? GQQ!X30DGflG£7 GODDGGQGG ©CM?
\5!7DO®D©S(Ifi© ©©[oXHCPGnuQQDQGo
MULTIMEDIA DRAWER
Holds 3.5” disks, minidata
cartridges or MD disc
cartridges. See Cat PI 94
for details. Cat. XC-4675
was $19.95
Save $4.00
12V/55W FOG/SPOT
DRIVING LIGHTS
Includes 2 lights and really nifty on/off
switch with
red/green
LEDs,
relay,
wiring loom
and
mounting
hardware. Size
x 85(D) mm.
Cat. ST-3070
The ultimate in burglar alarm PIRS. Requires
both the PIR & Microwave to be triggered at the
same time, substantially reducing false alarms.
was $79.95 Save $10 Buv a for <220
September $69.95
Cat. LA-5012
10 METRE RANGE
LCD VERNIER
m
For full specs see cat PI 21.
i
September $15.95
c=>'
TALKING
COUNTDOWN
DIGITAL INDOOR
THERMOMETER
Cat. QM-6320
3
Includes a clock.
Count up and down.
Includes a host of
features.
Cat. XC-0284
SAVE
UHF ANTENNAS
MAGNETIZER / cat lt -airs Was $34.95
DEMAGNETIZES
I . i — Save $5
43 ELEMENT
Cat. LT-3181 was $45
sept. $39.00
Cat. LT-3182 was $79.95
. $6
$io
Magnetized
screwdrivers makes
life easier.
Cat. TD-2042
CAR BATTERY GUARD
This guard prevents
the car battery from
running down
by switching
off automatically
when the battery
falls below
11.2 volts.
Supplied with
cigarette lighter plug and socket on lead.
Simply connect the device being used in line.
Maximum current is 10A.
Cat. AA-3092 Only $29.
12V HALOGEN
SPOTLIGHT
500,000 CANDLE POWER.
Cat. ST-3023
200PC SPRING
ASSORTMENT
■' ' // \ '
Cat. TD-2082
$109
NIBBLING TOOL
Normally$25.95
sept. $20
2KG DIGITAL SCALES
Cut any shape in aluminium,
plastic, copper and
unhardened metals to 18
gauge.Cat. TH-1768
Normally $21.95
Ideal for kitchen. Accuracy
+/- 0.5%. Resolution 1
gram/1 ounce.
Cat. QM-7245 $55
Cat. HP-0638
Leave both hands
free! Flip up
when not
in use. 4
different
magnifying
multiples. See
98 Cat. page 185
for details.
Cat. QM-3510
AURA.
rrjr,
Factor
ofr fhon
MJAJUttAl-
Plug it Into computer games, stereos etc, then 1
put the back pack on and feel all the low frequency
sounds. See 98 Cat. page 213 for full details.
Cat. XC-1000 ■■■ ft
AURA ADAPTOR CABLE FOR N64 & PLAYSTATION
This pack contains all the leads required to attach the Aura
Interactor to your games console and stereo system. Includes RCA
piggyback lead, 3.5mm phone to 2 x RCA adaptor lead, RCA joiners
and stereo Hi Fi RCA cable. Total value $17.40
Cat. XC-1001 $11-95
SAMSUNG SURVEILLANCE
Massive Distress Stock Purchase
Ideal for monitoring your front door, or the baby, etc. Includes a
10” black and white monitor, CCD camera in a metal case with
mounting bracket and 20mts. of cable. The monitor will accept up
to 4 CCD cameras, and these can be manually or automatically
switched between them. Any of our CCD cameras can be used
with this monitor. There is a talk function between the camera and
the monitor which has outputs to a video recorder. The monitor
runs off mains power, and the camera is powered by the monitor.
Extra cabling & the 6 pin mini plug are available.
Cat. QC-3490
Only $499
BUY 10 OF ANY PRODUCT LESS 10%
BUY S OF A PRODUCT WORTH $100 OR MORE LESS 10%
MAIL ORDER - FREECALL FOR PHONE ORDERS 1800 022 888 / NEW ZEALAND 0800 4529 227
MAIL ORDER - FREECALL FOR PHONE ORDERS 1800 022 888 / NEW ZEALAND 0800 4529 227
See 98 Catalogue pages 42/43
for full details.
JC25 BOOKSHELF
5” woofer and Vifa dome tweeter.
SPEAKER KIT Cat. CS-2585
$169Pr.
CABINET KIT Cat. CS-2586
$199PP.
Buy both togethei
JC30 6" 2 WAY
6” woofer and Vifa dome tweeter.
SPEAKER KIT Cat. CS-2590
CABINET KIT Cat. CS-2596
$199PP.
Buy both together $409
JV60 6" 3 WAY KIT
Includes 2 x 6” Vifa woofers and Vifa dome
tweeter.
SPEAKER KIT Cat. CS-2560
Buy Together for $849Pr
ZaX
RADIATION PHONE CASES
No one seems terribly interested in the fact that mobile
phones may fry your brains! Now you don’t have any excuses!
USER POINTERS
TYPE
Cat. ST-3102
Microtac
Motorola 8200, 8400
Motorola Flare
Motorola 8500, 8700
Nokia 2110
okia 1610
okia 8110
Nokia 5110
Ericsson 518/388
Ericsson 738/788
Cat. HC-6920
Cat. HC-6922
Cat. HC-6924
Cat. HC-6926
Cat. HC-6930
Cat. HC-6932
Cat. HC-6934
Cat. HC-6936
Cat. HC-6938 ,—
Cat. HC-6940
NEW BOOKS FROM
ELECTRONICS
AUSTRALIA
Basic Electronics
Cat. BE-5050 $5.95
Op Amps
Cat. BE-5060 $5.95
FULL INFO
NEXT MONTH
6500 8 SECTOR
COMPREHENSIVE
ALARM SYSTEM
Ideal for larger houses or simply
those that demand the ultimate
protection at an amazing price.
This is a pro system that would
cost a fortune if it was installed by a specialist
alarm installer. Do it yourself and
save a bundle! See page 77 of ‘98
Catalogue for full details. Cat. LA-5446
WHY BUILD A KIT?
5-INPUT STEREO MIXER
COMPLETE WITH 1 YEAR
WARRANTY
Why build a kit
when you can
use this pre-built
stereo mixer to
record your vinyl
records onto CD
using your PC
and sound card?
Many recordable CD drives now come with software
to eliminate annoying pops and cracks that are
sometimes associated with vinyl records. If you
need, commercial software and shareware is readily
available to facilitate vinyl to CD recordings. See
page 203 of our 98 Cat. for full mixer specifications.
12V AC plugpack required. Use our MP-3020 $16.95
Cat. AM-4200
SAVE
$$$$
„ JAYCAR
; WHOLESALE
All Jaycar products
are available at
very competitive
wholesale prices. If
you are tired of
your current
unreliable supplier,
why not give Jaycar
a try. You'll be
pleasantly
surprised.
LARGE COMPONENT
STORAGE TRAY
The third in a series
of resistor &
capacitor trays. This
one is the same
physical size, but
has 15 large storage
trays & is 34mm deep. Compartments measure 130mm
long, and are 11x45mm wide, 2x55mm & 2x78mm. Total
size 418(L)x275(W)x399(D)mm. Cat HB-6343 $11.95
Capacitor Tray Resistor Tray
45 Compartments IZhilJ
Cat. HB-6344 $11.95
•ICITAL MULTIMI
GREAT RANGE AT FANTASTIC PRICES!
For full specs see pages 20 to 25 of our 1998 catalogue.
88 Compartments Cat.
HB-6342 $11.95
INTERNET
PHONE!!!
Cat. XC-5100
See
July ads!
The "Full House
Power Driver
Consists of 32 odd driver bits:
•Tri-wing, Torx (tamperproof), Pin
drive In - Hex (alien), Torque .
Cat. TD-2035 WERE $29.95
ov
RNICHT PELI
IlfERYl
MAIL ORDER CORNER
Only available by ordfering from our Mail t)rder Department direct.
* NOT AVAILABLE AT OUR RETAIL OUTLETS
_ Call 1800 022 888 & have your credit card handy! ,
•Genuine Motorola Microtac Hands Free in Car Kit includes 3 watt
vehicle adaptor, (suits analogue & digital), cabling, brackets,
instructions etc. Brand new. No antenna. Dont pay up to $399 installed.
(Install yourself). Qty 30 sets only. Cat GG-1020 $129
•OPTUS 770 Analogue Hand Held Phone. Brand new unit with battery
and charger etc. Qty 7 only. Cat GG-1021 $50
•OPTUS 760 Analogue Hand Held Phone. Supplied with 2 batteries, case,
charger. Qty 1 only. Cat GG-1022 $70
•Motorola Digital Hands Free Adaptor Kit for "Brick". Including antenna
and all bits "n" pieces. Qty 8. Cat GG-1023 $50
•Mains Operated Sealed Lead Acid Battery Charger for use with 12V 4ah
transportable phone (Motorola 3680). includes mains adaptor and black
box. Qty 12. Cat GG-1024 $40
•Ericsson 4222-AU AC/DC Mains Adaptor/Charger. Output 12VDC
600mA. Terminates to 2 pin plug. Qty 20. Cat GG-1025 $io
•In-car Kit for Motorola Cellular 3 watt Carry Phone.
Incl mounting bracket, extension speaker, microphone
and cabling. Qty 6. Cat GG-1026 $70
•Motorola 3630/3680 Transportable Kit. Includes leather case, mains
adaptor 240V - 13.8VDC 650mA. Type SPN4193A, phone mounting
bracket, battery(l2V 2.3A) antenna, microphone, car power bracket and
lead. Qty 18. Cat GG-1027 $90
•Nokia/Optus N1000 Scaler Leather Cases Qty 25. Cat GG-1028 $s
•NEC P7 Scaler Leather Cases Qty 10. Cat GG-1029 $5
•NEC P310/Sportz Scaler Leather Cases Qty 32. Cat GG-1028 $5
•Motorola "Brick" adaptor to power unit from cigarette
lighter. Qty 9. Cat GG-1031 $5
•Motorola "Brick" Trtavel Charging Unit, includes mains and car adaptors
and charging plate/electronics. Qty 13. Cat GG-1032 $25
•Motorola "Brick" Extra Capacity Nicad Battery Qty 26. Cat GG-1033 $30
•On Glass Analogue cellular Antenna complete with base, lead,
instructions with TNC connector. Qty 10. Cat GG-1034 $15
•Magnetic Base Analogue Cellular Car Antenna. Qty 10. Cat GG-1035 $20
•NEC PS Rapid Charging Base. Base Only. Qty 20. Cat GG-1036 $5
Limited quantities available on these products.
Be Quick!!! All stock brand new.
PHONE PROTECTOR
PROTECT YOUR FAX
MODEM CORDLESS
PHONE ETC
This unit is designed to
protect both telephone line
and AC mains from surges.
Cat. MS-4025 $32.95
«tr:
V
6 WAY POWER OUTLET
WITH MAINS FILTER
Not only is it a six way power board, it
incorporates:
•VOLTAGE SURGE PROTECTION
•NOISE REJECTION FILTER NETWORK
•SPIKE PROTECTION ‘SAFETY CIRCUIT
BREAKER
Cat. MS-4030 $36.9!
>1
BRICK" GENUINE
7.5V
battery.
Don’t pay $50! These are now very scarce!
Brand new stock Cat. SB-2565
Only $20ea
CLASS ANALOGUE
CELLULAR CAR
Complete antenna with base,
lead, instructions etc. with mini
UHF plug. Limited quantity. Brand
new stock Cat. DC-4045
GENUINE MOTOROLA
“BRICK" CELLULAR
PHONE CHARGING
BASB/AC ADAPTOR
(14.5VDC
710mA)
Limited
qty
Cat. MP-3150 "
Brand new stock
Only $20ea'
CAR CELLULAR
WINDOW
ANTENNA
303X7 was
OUANTITY
Brand new
stock
Cat. DC-4046
Only $5e
CAR KITi
Includes clip
on microphone,
phone base
adaptor, extension
speaker (worth d
$16.95 on its
own) and cabling. Only 180
available. Ideal for re-installation of virtually
any phone. Brand new stock
Cat. YT-7080 only $25
email orders: maTlortiers@jaycar.com.au wholesale email: wholesale®
flavor
MHEEEI
ELECTRONICS
HEAD OFFICE
k 8-10 LEEDS ST RHODES 2138!
PHONE: (02)9743 5222
FAX: (02)9743 2066
Quality
Endorsed
Company
IS09002
Lie 6143
^Standards
Australia
WHOLESALE
PHONE: (02)9743 5222
ORDERS: 1900 620169
FAX: (02) 9743 3070
FREEFAX: 181
800 810137
MAIL ORDERS free postto:
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ENQUIRY HOTLINE: (02) 9743 6144 FAX: (02) 9743 2066
ROAD FREIGHT ANYWHERE IN AUST (up to 20kg) $14.00
POST & PACKING $10 to $24.99=$4.00 $25 to $49.99=$5 $50 to $99.99=$7 OVER $100=$8
ADELAIDE SA
BURANDA QLD
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CANBERRA ACT
MELBOURNE CITY
COBURG VIC
SPRINGVALE VIC
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_^Fax:(03)
AVAILABLE ON REQUEST I
•191-195 Wright St (Cnr. St. Lukes PI.) •Ph:(08) 8231 7355
•Fax:(08) 8231 7314 •Mon/Fri 9-5.30 •Fri:9-8 30 •Sat:9-4
•144 Logan Rd •Ph:(07) 3393 0777 •Fax:(07) 3393 0045
• Mnn/Fri-9-5.30 •Thurs:9-8.30 •Sat.9-4
• 1322 Gympie Rd, cnr Albany Creek Rd • Ph:(07) 3863 0099
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140 Campbell St. Hobart *Ph: (03) 6231 5877
- -
231 5876*Mon/Thur:9-5.30«Fri:9-7»Sat:9-4
SYDNEY CITY
BANKST0WN
GORE HILL
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PERTH
NZ
9267 1951
• 129 York St •Ph:(02) 92671614
-> •Thurs:8.3C
! Cnr Meredith•Ph:(02) 9709 2822*Fax:(02|9709
►Ph:{02]97(
2007 •Mon/Fri:9-5.30 *Thurs:9-8 3_0 •Sat:9-4 •Survl
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• 199 High St •Ph:(02) 4721 8337 •Fax:(02) 4721 8935
•Mon/Fn:9-5.30 •Thurs:9-8.30 •Sat.9-4 *Sun:10-4
•8-10 Leeds St •Ph:(02) 9743 5222 •Fax:(02) 9743 2066
Mon/Fri:9-5.30
‘OVERNIGHT DELIVERY
Subject to conditions: -Max weight 3KG (inc cubic) $10
•No dangerous goods *Max weight 5kg (inc cubic) $16
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H
Construction Project
Intelligent
Baby Alarm
Here’s an interesting and low cost project based on the popular BASIC Stamp
microcontroller module. It’s a flexible baby minder, which is easy to build and program
(from your PC), but also offers plenty of opportunities for adding extra ‘frills’.
by Owen Bishop
The ‘works’, with the BASIC Stamp visible at lower centre.
T his is a BASIC Stamp (or Counterfeit)
micro-based project, which can look after
baby more ‘intelligently’ than the typical
alarm system. Although it can be pro¬
grammed in Immediate mode to sound the
alarm every time baby makes a tiny snuffle,
the project works on the assumption that we
are not interested in the occasional sneeze,
cough or whimper that baby makes. It is only
when there are several such sounds within a
given period of time that we need to be
informed about it.
In its Normal mode the alarm registers
each disturbance, but it sounds the alarm only
when it has recorded a significant number of
disturbances within a few minutes of each
other. It is programmed to have a relatively
short memory, so that sounds made a few
minutes ago are automatically ‘forgotten’.
The parameters of the Normal mode can be
set both for the recording time interval and
the critical number of detected sounds.
The third mode, called the OK mode, is
one that is a novelty for baby alarms. This
gives us a reassuring beep or two every 10
minutes or so if it has detected no sounds in
that period. Nice to know that baby is sleep¬
ing quietly! The OK mode also includes the
Normal mode function and you can set dif¬
ferent parameters for sounding the alarm.
The alarm sounder, or audible warning
device (AWD) recommended for this system is
a low-level piezoelectric beeper. A device such
as this is perfectly adequate for normal domes¬
tic use. You could use a 120dB siren instead
and rouse the whole neighbourhood every time
baby hiccups, but do you really need to? An
LED is mounted beside the bleeper so we have
both audible and visible warnings.
Certain types of alarm system relay the
actual sounds from the nursery, but we find
this irritating — especially to guests. The
low-level beeper is much more discreet and
provides the warning just as effectively.
When the alarm is triggered, the AWD gives
five short beeps and then remains silent for
20 seconds. This gives you time to go to the
nursery, reset the system, and attend to baby.
The beeping is repeated every 20 seconds
until you do this, for there is no way of
switching off the alarm in the living room.
Discreet, but persuasive!
How it works
This design leaves scope for several modifi¬
cations according to your preferences, so we
have built it on stripboard. Fig. 1 shows that
the circuit is, as usual, centred around the
Stamp module, plugged into SKT1. The
other socket, SKT2 is for the programming
lead, connected to the PC during the initial
stages of testing and setting up the circuit.
The system runs on 6V DC and needs only
13.5mA when quiescent and about 60mA
when beeping. This means that it should run
for over 100 hours from a set of four type
AA alkaline cells in a battery-holder. Or you
can use a 6V DC (must be DC, but can be
unregulated) plug-pack.
The circuit has an LED (LED1) acting as
a pilot lamp. This is on the main board and,
since this is in the darkened nursery, we have
used a 330Q series resistor to limit the cur¬
rent to about 10mA. This gives quite enough
light to be seen in a semi-darkened room.
SW1 is the reset button; pressing this resets
the Stamp to run the program from the
ELECTRONICS Australia, September 1998
56
The complete schematic. The BASIC Stamp plugs into SKT1, while SKT2 is used to download its program from a PC.
beginning. Pins P2, P3 and P4 are used as
inputs to read the setting of SW2, the Mode
Select switch. This is a three-way rotary or
slide switch. These inputs are normally held
at logic low by the pull-down resistors R2 to
R4. The switch connects the selected input to
the +5V line (from the Stamp’s internal reg¬
ulator), taking it to logical high.
The switch we used for SW2 in the proto¬
type is a double-pole switch. It is feasible to
use the other half of this to switch on addi¬
tional LEDs to indicate which mode has
been selected, if you wish.
The output to the monitor board (located
in the living room) is switched by MOSFET
Ql, controlled by the output from pin P7.
Only a twisted pair of ordinary light-duty
cable (hook-up wire) is required to link the
monitor board to the main board. There are
two spare pins available (P5 and P6) so it
would be possible to program more elabo¬
rate warnings — for example to allow the
AWD and LED2 to be controlled individual¬
ly, but this entails having a cable of three or
more wires, which is more expensive.
Sound is picked up by the microphone
(MIC1) placed near baby’s cot. A cheap
crystal microphone insert is all that is need¬
ed, as we are not concerned about high
fidelity. The output from this is fed to an
operational amplifier (IC2) wired as a high-
gain inverting amplifier. The gain is
adjustable by means of VR1.
You could use a rotary pot for this,
mounted on the front panel of the enclosure
and provided with a knob. In practice the set¬
ting initially made is usually good enough
for permanent use, so a trimpot on the circuit
board does just as well. This also has the
advantage that it is inaccessible, so the sen¬
sitivity can’t be accidentally turned down.
The alternating output from the op-amp is
rectified by the two diodes D1 and D2, con¬
nected as a ‘diode pump’. Each time the out¬
put goes positive, current flows through D3
and increases the charge on Cl. D2 prevents
the charge falling when the output goes nega¬
tive. In a few oscillations the charge is pumped
up to a level sufficient to trigger the alarm.
The charge leaks slowly away from Cl
through VR2, which is set to give a level a
little below 2.5V. This it equivalent to a log¬
ical low at the input to the set/reset flip-flop
formed by the two cross-connected NOR
gates. The other input to the flip-flop (IC1,
pin 2) is held low by the output from pin PO
of the Stamp. In this condition there is a low
output from the flip-flop at pin 3, fed to
Stamp pin PI, programmed as an input.
When a sound is detected the voltage at the
wiper of VR2 rises above 2.5V and counts as
a high input to the flip-flop. This sets it, and
its output to PI goes high. This can be read
by the program, after which a low pulse at PO
is used to reset the flip-flop. The Stamp con¬
tinually reads the input at PI, and when a
high input is received it records that fact and,
if appropriate, sounds the alarm.
Construction
The circuit is best housed in a small plastic
enclosure (jiffy box). If you are powering the
circuit from a battery, use a box big enough
to hold the battery as well as the main board.
Mount a power ON/OFF switch on the front
of the enclosure.
Of the components on the main board,
only the reset button SW1 needs to be acces¬
sible. You may be able to mount the board so
that this can be reached through a hole cut in
the front of the enclosure. LED1 must also
be visible. As mentioned above, VR1 and
VR2 could also be mounted on the enclo¬
sure. The Mode Select switch SW2 also
needs to be mounted on the enclosure.
You could provide mounted sockets for
connecting the lead joining the main unit to
the monitor and to the microphone, but we
prefer a soldered connection as this is less
likely to become unplugged. If you are able
to locate the main unit close to the head of
the cot, the microphone could be mounted on
the enclosure. Coaxial cable is used to con¬
nect the microphone to avoid pick-up of
electromagnetic interference. The sheath of
the cable is connected at one end to the OV
rail of the board and at the other end to the
metal case of the microphone.
The monitor board is mounted in any con¬
veniently small plastic box, with apertures
for the sound and light to emerge.
When assembling the circuit note, that the
strips are cut in several places. In particular
note that there are NO cuts at HI5, LI5 and
M15 underneath IC1. Also note the solder blob
joining pins 5, 6 and 7 of the socket of IC1.
Testing it
The sound input interface is best tested
before inserting the Stamp in its socket. Use
a short length of wire to link sockets 1 and 5
of SKT1; this provides a 6V supply for pow¬
ering the ICs. In the same way, link socket 7
(PO) with socket 2 (OV) to ground the reset
input of the flip-flop. Use a test meter to
measure the voltage at the wiper of VR2.
This should be between 2V and 2.5V. Adjust
VR2, if necessary, to obtain this. Set VR1
about midway along its track.
Now make a noise reasonably close to the
microphone. The microphone is most sensi¬
tive to high-pitched shrieks and cries but, if
you are too embarrassed to make baby-nois-
ELECTRONICS Australia, September 1998
57
Construction Project
Intelligent Baby Alarm
Fig.2: The parts placement/wiring
diagrams for the two stripboards used
in the Baby Minder, plus the way a
* three-position slider switch is used.
c
D 1 2 3 4 5 6 7 8 9 10 11 12 13 U 15
J1 K1 El LI BOARD
5 V
C
es, or when your family gets fed-up with the
hullabaloo, clap your hands or flick your fin¬
gers instead. Such transitory sounds may be
over too quickly with a moving-coil meter,
but a digital meter will flash up some values
exceeding 2.5V. Measure the voltage at IC1
pin 3; it should be 6V.
Now reset the flip-flop by briefly connect¬
ing socket 7 to +6V. The voltage at pin 3
should have changed to 0V. Try setting and
resetting the flip-flop this way several times
to confirm that it works reliably.
Test program
With the Stamp in its socket (right way
round as indicated by the pin numbers ‘1’
and ‘14’ in Fig.2), and the programming lead
connected to the PC, switch on the 6V sup¬
ply. The marked side of the programming
lead socket goes to the end of SK.T2 marked
with a double-chevron in Fig.2.
Run the Stamp program on the PC.
Usually the first thing that happens is that the
alarm starts to sound. To get this under con¬
trol, type in the beginning of the first test
program:
‘Testitl
high 7
pause 1000
low 7
This causes a high output from pin 7, lasting
one second. The alarm sounds for one sec¬
ond and is then silent. Now type in the rest of
the program:
‘Testitl
high 7
pause 1000
low 7
readit:
input 2
debug #pin2
pause 100
goto readit
This is for testing the Mode Select switch.
58
ELECTRONICS Australia, September 1998
A closeup of the author’s main stripboard, with the BASIC Stamp module visible
just left of centre.
With the switch in position 1, the debug
command produces a series of ones on the
screen. Switching to positions 2 or 3 gives a
series of zeros. Edit the 6th and 7th lines of
the program to test positions 2 and 3 in the
same way. Now test the flip-flop action,
using Testit2:
‘Testit2
high 7
pause 1000
low 7
low 0
debug #pinl
high 0
low 0
debug #pinl
The initial one-second beep from the AWD
triggers the flip-flop (normally the AWD is in
another room, so it doesn’t trigger the sys¬
tem). The ‘low O' puts the reset at zero, which
does not affect the flip-flop. The first debug
displays a ‘ 1\ showing that the flip-flop is set
(by the bleep). The high 0 followed by low 0
resets the flip-flop and the second debug dis¬
plays 0, showing that this has been done.
If you amend the first line to ‘low 7’ there
is no sound from the bleeper and both
debugs give a 0. Also try making a noise
(clap etc) during the initial 1-second of
silence, to obtain 1 followed by 0. This com¬
pletes the testing.
Programming
The program given in Fig.3, together with its
flow chart, illustrates the main features that
an intelligent baby alarm might have, but
there is plenty of scope for you to modify it
and add your own facilities. The program
occupies about two-thirds of Stamp’s mem¬
ory, so there is enough room to spare for a
few more routines.
We have left two of the Stamp’s pins
unused, so there is the possibility of interfac¬
ing additional circuitry.
The program begins by turning on the
beeper for one second. This confirms that
the program is running and also that the
electrical connection to the monitor board is
intact. Then we put the Stamp to sleep for
two minutes (if only baby would go to sleep
so obediently, there would be no need for an
alarm!); this is to give you time to say your
goodnights and get out of the nursery, and
for baby to settle down. After that, the pro¬
gram resets the flip-flop and reads the mode
select switch. This sends it to one of three
routines called ‘one’, ‘two’ and Three 1’.
Routine 1 is the Immediate mode, which
sounds the alarm as soon as any sound is
detected. You might want to use this if baby
is sick. The Stamp reads the flip-flop output
continuously and, as soon as it goes high,
jumps to the alarm routine. There is no way
back from this; it loops round a circle of
commands, producing five short beeps every
20 seconds until you go to the nursery,
attend to baby and reset the program.
Routine 2 is the Normal mode, which
waits until a specified number of sounds
have been detected during a specified period.
Subroutine Record waits in a loop while
word wO counts up from 1 to 6000 (this takes
about 75 seconds). If a sound sets the flip-
flop during this period, b2 is set to ‘1’.
Otherwise it remains ‘O’. The subroutine
adds the latest value of b2 to the values in the
other registers b3 to b9, and so obtains (in
blO) the number of sounds detected during
the previous 10 minutes.
If you want a shorter period, reduce the
number of repetitions of the loop (for exam¬
ple ‘for w0=l to 2000’). If the number
Fig.3:
Program Listing
baby3
high 7
pause 1000
low 7
sleep 120
high 0
low 0
bO=pins & 28
if b0=16 then threel
if b0=8 then two
one:
high 0
low 0
pause 2
bO=pinl
if b0=0 then one
goto alarm
two:
gosub record
if bl0>3 then alarm
gosub shift
goto two
threel:
bll=0
three 2:
gosub record
if bl0>2 then alarm
if bl0>0 then skipl
bll=bll+l
skipl:
if bl0=0 then skip2
bll=0
skip2:
if bll=20 then OK
continue:
gosub shift
goto three2
alarm:
for bO=l to 5
high 7
pause 200
low 7
pause 200
next
sleep 20
goto alarm
record:
high 0
low 0
for wO=l to 6000
b2=pinl
next
bl0=b2+b3+b4+b5+b6+b7+b8+b9
return
shift:
b9=b8:b8=b7:b7=b6
b6=b5:b5=b4:b4=b3:b3=b2
return
OK:
for bll=l to 3
high 7
pause 50
low 7
pause 100
high 7
pause 300
low 7
pause 100
next
bll=0
goto continue
ELECTRONICS Australia, September 1998
59
RfcAUtht INFO NO.20
Construction Project
Intelligent Baby Alarm
PARTS LIST
returned in blO exceeds 3 (more than three
sounds during the last 10 minutes), there is a
jump to the alarm routine and the action (for
the program and you) is as before.
You can alter the ‘if b 10>3’ line to anoth¬
er value if you prefer. If the number of
sounds has not reached the triggering limit,
the values in B2 to B9 are shifted along, so
that the value currently in b9 is lost (a sound
made 10 minutes ago is ‘forgotten’, and b2 is
copied to b3, ready to put a new value into
b2 the next time round).
Routine 3 is the OK mode. It has the
same alarm-triggering features as the
Normal mode, but takes a more positive
viewpoint by letting you know if baby is
sleeping calmly. Information about this is
stored in bl 1, which is set to zero at the
beginning of the routine.
In our version of the routine we trigger
the alarm after two sounds, but you can
use three as before or any other number.
Each time round the routine, bl 1 is incre¬
mented by 1 if no sounds have been detect¬
ed; if a sound has been detected, bll is
reset to 0. When bl 1 reaches 20 (meaning
25 minutes without a sound) the bleeper
makes a reassuring ‘de-dah-de-dah-de-
dah’ signal, but only once. After resetting
bll to 0, the program continues monitor¬
ing sounds as before.
Resistors
(All 5%, 0.25W)
R1 330 ohm
R2-4, R9 10k
R5 100 ohm
R6 4.7M
R7, 8 lk
VR1 2M trimpot
VR2 1M trimpot
Capacitors
Cl InF greencap
Semiconductors
LEDl, 2 LED, red
Dl, 2 1N4148 silicon diode
IC1 4001 CMOS quad 2-input NOR
gate
IC2 TL081C JFET op-amp
Q1 VN10KM or similar N-channel
MOSFET
Miscellaneous
Stamp BS1 (or Counterfeit) module, with
software and programming lead.
MIC1 Crystal mic insert or other crystal
Operating it
The operation of the Intelligent Baby Minder
is really very straightforward, and can be
summarised in four steps;
1. Switch on, listen for the initial one-second
beep, and select the mode you want.
2. Put baby in cot, press reset button, leave
the nursery.
microphone
SW1
Pushbutton switch (PCB mount
SPST momentary)
SW2
Miniature PCB mount DP3T slide
switch (or rotary)
SKT1
Three-pin header, straight (buy 40-
pin and cut to length)
SKT2
14-pin header sockets (buy 40-pin
and cut to length)
Piezo audible warning device, PCB mount, 3-16V
DC, 75mm pin spacing; 14-pin DIL socket; 16-
pin DIL socket; single core shielded audio cable;
stripboard 40mm x 81mm (15 strips x 31
holes), and approx 28mm x 40mm (11 strips x
15 holes); 12 x 1mm terminal pins; plastic
enclosures for main unit and monitor; Battery
clip/battery box/mains plug-pack.
NOTE: The BASIC Stamp BS1 and Counterfeit
modules are both available from MicroZed
Computers, of PO Box 634, Armidale NSW 2350.
Phone (067) 72 2777 or fax (067) 72 8987.
Their Web site is at
http://www.mlcrozed.com.au/~microzed, or you
can e-mail them at bob@microzed.com.au.
3. A five-fold beep (and flash) repeated
every 20 seconds indicates that baby needs
attention. When baby has been re-settled
again, press the reset button to re-start the
program.
4. If you are using OK mode, a ‘de-dah’
beep (and flash) tells you that baby is peace¬
fully asleep. Enjoy the TV and pizza! ❖
3
[M
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ELECTRONICS Australia, September 1998
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READER INFO NO.21
T raffic jams! Aren’tya sickathem?
Everywhere you go nowadays, you
seem to be not going at all, but sitting
there in your car waiting to move forward a
few metres. Or when you do move, it can get
downright scary.
My home, nowadays in Port Townsend,
Washington, shouldn’t have traffic jams,
because its population is only 8000 people.
As well, Port Townsend is at the end of the
road; it’s not on the way to anywhere,
because it’s located on a peninsula and is
surrounded on three sides by the sea. So traf¬
fic goes to Port Townsend, stops, turns
around, and goes away again.
The cars per unit of road are not many —
but still, everything is slow. For one thing,
speed limits are ridiculously slow — such as
40km/h along a big wide highway that
would be 80km/h in Australia.
Add to this the town’s large pop¬
ulation of senior citizens, and
suddenly things are moving very
slowly indeed.
There are categories into
which drivers may be placed, in
descending order of speed of
travel (please pardon lapses of
political correctness here...):
0: A normal, uninhibited driver.
(See photo, a sign on my own
car...)
1: The driver of a large
American sedan — Buick, Oldsmobile, etc.
2: Sedan driver with headlights on in the
daytime, for ‘safety’.
3: Sedan with lights on, driven by an old
man wearing a hat.
4: As in 3, with wife in back seat.
There are further categories of course, spe¬
cific to Australia:
5: Car displaying bowling hat on back parcel
shelf.
6: Car driven by old lady wearing bowling
hat.
7: Car with four old ladies wearing bowling
hats.
8: A hearse.
Seattle, Washington (not far from my
home) has what’s considered the worst traffic
for a city its size in the USA. Like so many
American cities, Seattle is blessed (or plagued,
depending on your point of view) with free¬
ways, part of the interstate highway system.
And these might not be free much longer...
These super-roads bisect many cities up
and down, left and right. In Seattle’s case
Interstate 5 (1-5) runs north and south along
the city’s backbone. About midway along, I-
90 runs east and west. Another freeway
known as 405 runs through Seattle diagonal¬
ly. These roads are sources of great frustra¬
tion, and sometimes great adventure.
During non-peak times, there is plenty of
traffic, but it flows freely — very freely. There
is a speed limit of lOOkm/h, which means
everybody goes at 140, except when there is a
cop around. The freeways carry anything up to
five lanes in each direction, and they are filled
with semitrailers as well as cars.
So sometimes you’re barreling along with
the flow of traffic, with one semi behind you,
one in front and one on each side, all moving
as a mass at 140km/h. If the truck at your left
decides he wants to be in your lane, he will
signal, blast his air horn, and then begin
merging right. Your job is to apply the brakes
in such a way as to be out of his way when he
begins to occupy your space — while not
being rear-ended by the semi behind you.
For us country bumpkins, a trip to the big
smoke is a trying time indeed. Imagine what
it’s like then, when the above-described
mass of moving metal comes upon a Type 3
driver chugging along in the centre lane at
50km/h. That’s Seattle traffic, and there are
many prangs every day, all dutifully
announced on radio traffic reports by over¬
head aircraft.
Most of my trips to Seattle have been to
pick up or drop off someone at the airport.
This involves a trip of more than 160km,
along both shores of Puget Sound. To be
sure of getting to the airport by the required
time, one must allow three hours, although a
really good run can take only half that.
Along the west side (my side), it’s usually
fairly easy sailing until you get to the place
where you actually cross Puget Sound — the
Tacoma Narrows. Here there’s a big suspen¬
sion bridge which is world famous because
of some film of it taken during a storm. The
wind got the whole bridge vibrating at its
resonant frequency, and the film showed it
twisting violently back and forth, merrily
tossing cars about.
The bridge has been redesigned now, with
its resonance damped. But it’s
still fun to collect some new
arrival at the airport, and then
when exactly the right moment
comes, you say, “Remember that
TV film of a bridge twisting and
bucking? Well, you’re sitting
right in the middle of it!”
There are still people living in
the Seattle area who to this very
day refuse to go anywhere near
the Tacoma Narrows bridge —
they take the ferries instead, at
great expense and at risk of late
arrival due to overcrowding.
I mention the Tacoma Narrows bridge
because it is the traffic jam champion of the
Pacific Northwest. The bridge has two lanes
in each direction; you’d think that would be
enough. But when traffic hits that bridge it
slows to a fraction of normal speed. Maybe
that’s because drivers are afraid of starting it
shaking again.
Once cars are on the other side they start
moving properly again. But for cars on the
input end of the bridge, traffic comes to a
start/stop standstill, and in peak hour this can
extend up to 20km each side of the bridge.
And if there’s a prang on the bridge
ooohh! That’s why you have to allow three
hours to get to the airport.
These are big problems for traffic planners.
“If the truck on your left decides he wants to
be in your lane... your job is to apply the
brakes in such a way as to be out of his
way when he begins to occupy your space
— while not being rear ended by the semi
behind you.”
62
ELECTRONICS Australia, September 1998
There’s already a scheme to build a second
bridge next to the Tacoma Narrows bridge, or
perhaps a second deck on the main bridge, to
ease traffic flow. But the roads feeding into
each end of the bridge are two lanes each
way; the bridge itself has two lanes each way.
How is doubling the lanes across the bridge
going to make any difference? If drivers are
still afraid of the thing collapsing, they will
still go slow. And the current plan is to slap a
toll on the bridge to pay for its expansion,
making it just as expensive to use the bridge
as to take the ferries.
Now traffic planners are starting to
realize that traffic congestion can’t be
solved by simply building more
roads, because traffic always seems to
increase to fill whatever roads are
available. Instead they are starting to
find ways to make the most efficient
use of what’s already there.
Traffic authorities in Seattle, and
some other cities, are already using
lanes called ‘HOV’ lanes (high
occupancy vehicle) on 1-5. These
are usually the innermost lanes, set
aside for cars with at least two peo¬
ple in them, and buses. At the same
time, trucks may be limited to the
two outside lanes, so the speed of traffic
follows a gradient from the outside to the
inside lanes.
However, since most cars particularly at
peak hour contain only the driver, the HOV
lanes are badly underused and therefore not
really efficient. But the going is certainly
good for those who DO use the HOV lanes,
except for one stretch of 1-5 where the HOV
lane has two wheels on concrete, and the
other two wheels on bitumen. It’s a strange,
and worrying, way to travel.
Now clever traffic engineers are working
out ways to make more efficient use of HOV
lanes. This involves declaring HOT (high
occupancy toll) lanes, the idea is to let multi¬
person cars use the lanes as normal, but also
allow solo drivers to use the lanes — at a price.
A toll will be charged, low enough to encour¬
age efficient filling of the fast lanes, but high
enough to keep them from getting jammed.
The idea is to keep a fairly constant flow
going in the HOT lanes, regardless of whether
or not it is peak hour. So it’s intended to vary
the HOT lane toll dynamically, depending on
the time of day and measured traffic volume.
The problem is that you can’t very well stop
every car to collect the toll; that would pro¬
duce more, rather than less, congestion.
So — electronics to the rescue! Every dri¬
ver who intends to use the express lanes will
be set up with a special account. His car will
be equipped with a small transponder which
sticks to their windscreen with Velcro. As a
driver approaches the start of an express
lane, there will be an electronic sign advising
the current price. This might vary from SI .50
when the lanes are wide open, up to $4.00 at
peak hour. As the car progresses along the
express lane, radio equipment interrogates
the transponder, taking note of its account
number. Then the toll can be automatically
extracted from the driver’s Visa or
MasterCard.
Tom emailed us this pic of his current
car’s number plate, with its surround
message neatly summarising his feel¬
ing about driving conditions...
This system is already being used in San
Diego, California, from the beginning of
April this year. When transponders came on
the market, the initial 1600 were snapped up
in the first week. Now there are more than
2500 in use, and that number is expected to
double before long.
Knowing the capabilities of the electron¬
ics in this system, it’s possible to think of
some further refinements. If each transpon¬
der were interrogated, say every kilometre,
and if there were frequent electronic signs,
then you could encourage drivers to move in
and out of the express lanes at will.
If congestion in the express lane becomes
too heavy, you could raise the toll by fifty
cents or so, displaying it on the electronic
signs. A certain proportion of drivers would
decide it wasn’t worth it and move to slower
lanes. Then the transponder would disappear
from that lane, and toll charging would stop.
If express-lane traffic decreased, the toll
could be lowered and cheapskate drivers
would move back into the express lane.
Since transponders would be interrogated
periodically, it shouldn’t be too difficult to
measure the amount of time drivers spend in
the express lanes and charge accordingly. If
they’re paying by the minute, it would
encourage everyone to go the speed limit
instead of dawdling. And, if someone was
speeding, the system could compare time
versus distance covered and whack him with
a mail-order speeding ticket.
This dynamic-pricing system sounds
attractive, but in practice, how much con¬
gestion could it actually relieve? According
to John Semmens of the Arizona
Department of Transportation, you’d have
to convert the entire road system onto
dynamic pricing. But if that could be
achieved, overall congestion could be
reduced by 10%, fifty times as much as
a light-rail system might eliminate.
And it would be 140 times as cost-
effective as rail, says Semmens.
There are, of course, social concerns
here. It’s felt that the system would dis¬
criminate against less well-to-do drivers
who could not afford the tolls (they’re
calling the new express lanes ‘Lexus
Lanes’). But even then, less prosperous
drivers would still benefit from less
congestion in the ‘Peon Lanes’ as the
Lexi moved into the express lanes.
Is this plan useful in Australia?
That’s hard to say. I’ve seen some whop¬
per traffic jams in Oz, especially when I
was living in Melbourne. But they don’t
hold a candle to the horror that happens
daily in Seattle....
Still, this might give you some ideas to
discuss with your local politician as you sit
there tapping your toe, waiting for traffic to
start moving again. ♦>
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ELECTRONICS Australia, September 1998
63
READER INFO N0.22
ALTRONICS C""'5f?ENTS
earning II?
You will be amazed with the incredible realism of your favourite
music tracks with these fantastic C 3300 D.I.Y. Home Theatre
Loudspeaker Kits! This month we have also introduced a new 70W
IRODA GAS Irons PLUS the new feature packed A 1200 Bike
Computer has just arrived! I urge you to place your order promptly,
as many of the items are in high demand and will not last at these
prices. Remember our EXPRESS JET SERVICE will deliver your
order FAST!
(Country areas please allow
an additional 24*48 hours)
Remote Control
, ^ This learning remote control can
fflv replace up to eight remote
IB controls! Featuring: • 8 Appliance
V Modes • 2 Auxiliary Modes
IB • Intelligent Backlighting - Once
I--Activated, dims away
Get rid Of your after being idle for 5
Coffee table remote seconds, saving batteries!
clutter with this (Unlike others on the
amazing unit! market) Requires 4 x AAA
-1 batteries (supplied). See
97198 Cat. pl70
A 1000 Normally $ 199 , NOW $-1 69
Best Regards,
Jack O’Donnell, Managing Director
Hi-Fi & Home Theatre Loudspeaker Kit
"They sound great with any music from K
classic to rock, from Mozart to Metallica/'^fi
Leo Simpson , Silicon Chip Magazine
Designed by acclaimed Australian loudspeaker designer
Richard Priddle, these speakers are engineered to deliver superb
sound quality whilst being incredibly simple to assemble.
• Enclosures. The cabinets are precision crafted on CNC machinery from
high quality MDF material, and feature a new and simple construction
method which provides incredible joint integrity. Each panel is cut with
close-tolerance precision to ensure the enclosures fit together as designed,
without leaving unsightly overhangs, leaking air gaps or mis-matched
veneer. All driver, port and terminal holes are pre-cut and recessed. Speaker
grille is pre-covered in acoustic cloth ready to fit.
• Drivers. The loudspeakers feature our new series of polypropylene hi-fi
drivers, exclusive to Altronics in Australia. The 6.5" woofers produce deep,
punchy bass and maintain their response through the mid-frequencies to
provide a linearity of response most two-way systems cannot hope to
reproduce. The fabric dome tweeter handles the most demanding of top-end
program with ease, producing crisp, clean highs and exquisite detail.
• Crossovers. The crossover has been computer-optimised to deliver the
best sound quality when coupled with these drivers and enclosure. It uses
high quality capacitors and low-impedance inductors to minimise signal
colouration and phase-error.
• Kit Components. The kit includes flat-packed cabinets, drivers,
crossover components, terminals, speaker wire, port tube, acoustic wadding
and detailed assembly instructions. In fact, all you need except a bottle of PVA
adhesive.
FEATURES: • No electronics expertise required. Simple step-by-step
assembly instructions included. ■ No special tools required, all HflRl
sections are pre-cut and machined. Typical assembly time 2 to 3
hours. • Fully pre-assembled 2nd order, impedance matched
crossover. HjjMB
• Everything supplied, all you will need is PVA adhesive.
plus delivery j
LCD Bike Computer
This compact bike computer f~
is a must for serious »■■ ■■ ■ 1 _-
cyclists! It has all the
standard features ftJBBBBB|pBB\
you’d expect PLUS UM •O' ®;
for added security
you can simply
detach it from the
bike and put it in
your pocket once j
■BBBBH^I
• Current Speed • Average Speed H
• Maximum Speed • Trip Time S
• Trip Distance • Total Distance
(Odometer) • 24Hr Clock Time • Countdown Timer
• Countdown Distance. Supplied with mounting
brackets, magnetic pickup, spoke magnet, even the
battery! (Valued at $3.95)
A 1200 Normally $37.95 NOW$ 2 9 -95
C 3300 Complete Kit
plus delivery
CA3300 Kit(Less Cabinet)
CB3300 Cabinets Only 4^. ^7
Delivery Fee of $25 applies to C 3300 and
$12.50 applies to CA3300 & CB3300
plus delivery
Gas Powered
Soldering
Irons
Keychain Model. This laser pointer weighs only
45g, with batteries, and comes complete with a keychain." 1
Measuring only 61mm long by 14mm in diameter, it s not
much bigger than many keys! It emits a very intense
beam that can travel up to 50m, and projects a —
bright red dot onto the target is it aimed at. It's
ideal for lectures, guided tours, seminars, building
sites etc, and it's much less intrusive than a normal
stick pointer! Uses two button batteries (included).
A 0201 Normally $69, NOW ONLY $35
The advanced IRODA Soldering Iron offers
go-anywhere soldering convenience. It features a thumbwheel
heat control, cap mounted igniter, long life catalyst tips and a
huge gas reservoir for long use-time. The kit consists of the
IRODA Gas Soldering Iron supplied in a handy carry case
y with a range of tips and accessories.
\ Features: • See-through gas chamber • Igniter built
— j into cap • Uses standard butane gas • Supplied with
safety stand, cleaning sponge, solder dispenser, blow
torch, hot air blower and hot knife cutter
WARNING Vfl UHill iniEflSIIY LASER PPfflTEBg
Whereas we are unaware of any of our customers (being principally engineers and electronic enthusiasts)
irresponsibly using laser products, pointing towards the eye of any human or animal could cause eye damage
and lead to criminal charges. Altronics is limiting the power output rating of all new stocks to lmW. Current
stocks (approx. 3mW) are not available to persons under 18 years of age and are sold on the strict
understanding they will not be left where they could fall into the hands of juveniles or irresponsible persons.
T 2592 Complete Kit with Accessories, will retail for $89 9S
j SPECIAL INTRODUCTORY PRICE ONLY $69”
T 2590 Gas Iron plus Blow Torch Tip, will retail for $49 95
!! SPECIA L INTRODUCTOR Y PRICE ONL Y $39 95
SaiRSlW The first 100 callers Jo
purchase either a T 2592 or T 2590 qualify for our FREEbonus
offer of a roll of T 1100A solder and a T 2447 Butane Refill,
tooether valued at $12.95 MIES®@lL(U>YlBtL V Ir-lfSlkLsB _
Pen Model. This stylish slimline laser pointer is housed in a sturdy metal
case about the same size as a fountain pen, and includes a pocket
clip. Ideal for lectures, guided tours, seminars, even
building sites, and its much less intrusive
than a normal stick pointer! Push-to-
activate operation. Uses two AAA cells
(included!). Supplied with soft
leatherette storage case.
A 0200 Normally $99, NOW $49
Exclusive to
Altronics and
Dealers!
Micro Jet Blow Torch
Powered by a refillable gas
lighter (supplied), tins blow ,, .
torch burns at 1300’C.
making it Ideal for all types ot
brazing and heavy duty
soldering It can bo ignited and
used with one hand, and the in¬
built piezo electronic Ignition
ensures easy lighting every time
Ideal tor the workshop, _
lool box, work bench
etc. ■■■■
T 2490 WAS $24.95,
“Virtually anyone can construct these
speakers, whether they have wood-working
skills or not. No special tools are required,
although you will need a bottle of PVA glue.
Once assembled, you will have a set of
speakers you can really be proud of. In my
opinion, these are comparable to speaker
systems costing $1000 or more. In fact, they
look and sound so good, your friends will
not believe you built them yourself.
Leo Simpson, Silicon Chip Magazine
1 -800 999 007 PERTH (08)93281599
OVERNIGHT DELIV
Central Door
Locking Kit
All four doors will automatically lock or
unlock with the operation of either of the
front doors. Add the ease and convenience
of central locking to your car. Can be interfaced to
our S 5205 car alarm (and others) to lock or unlock
all four doors when the alarm is remotely armed or
disarmed. Kit includes everything you need to fit
central power locking to your vehicle; module, solenoids, rods & couplers,
grommets, punched strip, screws & clip nuts, even the wiring harness! The
actuators are motorised with an inbuilt gearbox to ensure reliable and positive
operation. One actuator is mounted inside each door. Includes central control
unit which mounts under the car dash. For use with 12V negative earth systems.
S 5241 Normally $119 ea, NOW A CRAZY $69
qELLOUTlLimitcd
Stock, Be Quick!
/Not available from dealers)
TITAN Remote
Car Alarm
SPECIAL OFFER
Purchase both the
S 5205 and S 5241 for just
$229 for the set!
Don’t let car thieves make off with your
pride and joy, install one of these
security systems and save $$$ on
comparable units.
Secure your vehicle with this versatile
TITAN car security system.System kit
includes alarm module, two remote
controls, battery backup siren, shock sensor,
valet switch, status LED, wiring harness
and hardware. Features: • Two remote
controls • Super Loud 127dB siren
• Remote panic • Battery backup and
tamper proof siren • Child proofing and
anti intrusion alert while driving • User selectable exit
delay and auto re-arming • User selectable arming/disarming chirp
• Starter kill • Valet mode • Automatic shunt of defective entry zone • Alarm
memory indicates which zone (1-3) triggered • 60 second siren with auto reset
• Two colour LED indicator • Can be interfaced with central locking (where
fitted) • 3 extra channels on remote to control features such as boot release, etc.
S 5205 Normally $229, NOW $1 69
Desoldering Tool ”■*
Easily desolders a 14pln 1C In around 30 seconds. Once desoldered, ih *
component virtually falls out!
The T 1280 MICRON SURE SHOT Desoldering Tool makes it a breeze to
remove components from any PCB, even double sided, through-hole plated
boards. All it needs is a squeeze or two on the trigger and the component
virtually falls out. Features: • Totally self contained • Light and compact
• Anti static tip • Safe & easy to use • Simple to clean and
maintain • Variable tip temperature.
hii'ul far service techs , manufactur ers, R &D centres, enthusiasts.
T 1280 Was $349 NOW ONLY $299
T 1282 1.0mm Replacement Tip $34.95
T 1283 1.6mm Replacement Tip $34.95
30W Variable Tempi
Soldering Iron
Tip temperature is adjustable from
250°C to 450°C. Select the right
temperature for the job and
avoid heat damage to sensitive
devices! Features ceramic
heating element and supplied
with 1.6mm conical tip. 3 other tip
sizes available. See 1997/98 Catalogue pill.
T 2446 Normally $55, NOW $49
Micron Soldering Station
AS USED BY MANUFACTURERS AROUND AUSTRALIA!
Electronic Temperature Controlled Soldering Station
The ultimate in controlled temperature hand soldering for hobbyist and
professional applications. Features • Huge 60 watt heavy duty element
• Dial up temperature control with ±1°C stability at idle • Temperature
range 250°C to 450°C • Ceramic heater element with embedded
thermocouple for ultra-fast heat recovery • Zero voltage switching to
minimise voltage spikes at tip • Low voltage element for added safety • Built in
sponge tray with tip cleaning sponge • Full range of replacement long-life tips
available • CMOS-safe grounded tip
T 2441 Normally $199, NOW $1 29
UpTeK Professional Digital Multimeters
Altronics has been appointed Australian distributor for this fine range of UpTeK digital
multimeters. These superb meters are ideal for the hobbyist and professional alike. All feature UL
approved fuse protection on current inputs, large high contrast 3.5 digit LCD displays, high
quality instrument leads, built-in stand and rugged construction. If you want the best performing
multimeter for your dollar, then look no further than these excellent instruments.
All are supplied with high quality, silicon rubber insulated instrument test leads.
Save a MASSIVE $70!
Features ceramic element with embedded
thermo couple for ultra-fast heat recovery.
Ideal for the hobbyist or professional!
6 Input Stereo Mixer
43 Range LCR DMM
• 20MHz Frequency Counter
• Incorrect Lead Socket Beeper
• Peak Hold & Data Hold
• Auto Power Off
• Inductance < 2mH - 20H
• Capacitance < 20nF - 2000pF
• Frequency < 2kHz - 20MHz
• AC Volts < 200mV - 750V
• DC Volts < 200mV - 1000V
• Resistance < 2000 - 20ML2
• Continuity Buzzer
• AC/DC Current < 200pA - 10A
• TTL/CMOS Logic Tester
• Diode Check
Q 1108 $1 39
Auto Ranging DMM
• 32 Segment Bar Graph
• Manual Override of Auto-ranging
• Incorrect Lead Socket Beeper
• Range Hold & Data Hold
• Auto Power Oft
• AC < 320mV - 750V
• DC Volts < 320mV -1000VDC
• Resistance < 3200 - 30MO
• Continuity Buzzer
• AC/DC Current < 320pA - 10A
• TTL/CMOS Logic Tester
• Diode Check
Q 1104
$11 9
30 Range DMM
• Temperature -50°C to 1100°C
• Data Hold
• Auto Power Off
• AC Volts < 200mV - 750V
• DC Volts <200mV- 1000V
• Resistance < 2000 - 20MO
• Continuity Buzzer
• AC/DC Current < 200pA - 10A
• Diode Check
Q 1102 $1 09
Q 1103 Thermocouple $1 5
nnn
.uuu
TRUE RMS 34 Range DMM
• True RMS AC measurement to 5kHz
• Frequency Counter < 2kHz - 20MHz
• Data Hold
• Auto Power Off
• Low Ohms Capability (< 20i2)
• Zero Adjust on Low Ohms
• AC < 200mV - 750V
• DC Volts < 200mV - 1000VDC
• Resistance < 200 - 20MQ
• Continuity Buzzer
• AC/DC Current < 200pA - 10A
Q1106$1 1 9
RP M//s MONTH! Purchase any one of these
carry holster (Q 1115), valued at $12.95, absolutely FREE-
Great for dubbing videos, multimedia, or as a basic PA
mixer. Two 6.35mm mic inputs, two RCA stereo line
inputs, and two RCA stereo phono inputs. Assignable
headphone monitor, LED output level indicators and two
stereo outputs.
A 2540 1998 Price $149, NOW $99
NiCad Batteries
GOOD FOR 100’S OF RECHARGES!!
NiCads will eventually pay for
themselves, and can provide
hundreds of recharges if cycled
periodically. They can be used in j
just about any battery powered
appliance.
HUGE SAVINGS!
S 4705 700mAh AA Cell Normally $2.50 ea,
NOW $2 ea, 10 & up, or $1 ' 60 ea, 25 &up
S 4710 1500mAh C Cell Normally $4.95 ea,
NOW $4 ea, 4 and up, or $3 50
ea, 10 & up
S 4715 1500mAh D Cell Normally $7.25 ea,
NOW $4 ea, 4 and up, or $3 75
ea, 10 & up
S 4720 lOOmAh 9V Cell Normally $12.95 ea,
NOW $8 ea, 2 and up, or $7' st * ea, 4 & up
RTH mn\ Q39ft 15QQ
ONIC
MPONENTS
CLASS A Audio
Amplifier Kit
(See Sc July '98) This kit is a must for any serious
Audiophiles who demand a highly accurate
reproduction of their favourite music. Class A amplifiers
typically have peak distortion less than twice the average
distortion of class AB amplifiers, figures that are almost unmeasurable
(typically in the order of 0.0005% ). Specifications: • Signal to noise ratio of -115dB (un-weighted)
and - 119dB (A-weighted) • 15W rms into 8 D • No Crossover Distortion at low power
K 5109 $49 H 0545 Heatsink to suit $23.95
K 5110 Regulated Power Supply to suit $26.95
Motorcycle Helmet Beat
Intercom Kit Triggered
Strobe Kit
Video Fader Kit
Add professional "IP”
& fades to your home
videos'. Even inc ' ude
an enhancer to boost
lh e edited signal.
1/1
Allronlca Kit
comoB
boudsof/inic!
(See EA July '98)
Communication between
the rider and pillion
passenger on a motor¬
cycle can be difficult when
you are moving at lOOkph.
This project allows hands
free communication
between the rider and
passenger of a motorcycle. Features:
• Separate battery supply (4 x AA) or
motorcycle system supply • Low & high pass filters
to reduce vibration & wind noise through the mic
• VOX on/off • Single volume control for both
channels • Supplied in an attractive case small
enough to fit into a jacket pocket.
K 5270 $45 (Helmet not supplied)
(See SC Aug '98)
You've seen these in
Nightclubs and rock concerts.
Strobes add super lighting
effects in darkened entertaining
area’s. It is sure to add tons of
life to any party or B.B.Q. Features • Variable rate and
sensitivity for beat settings • Line source inputs for beat
triggering • Selectable beat / continuous functions •
Simplified construction to it's predecessor • Powered
from a standard 240V mains source • MDF box, carpet,
robust aluminium reflector (unlike others on the market)
and all the necessary components for a single strobe
model. Also available is a second tube option for those
who need twice the light.
K 5792 $1 59
(See EA April '98)
Got »oiv\e hum# videos you'd like to edit
properly for keeps? This useful kit allows you to
add basic professional video effects such as
horizontal and vertical wipes, fade-ins and fade-
outs during your editing. Features: • Wipes
_J horizontal and vertical • Fade or wipe to black or
white • Supports both BNC or RCA inputs • Built-in
switchable signal enhancer so you'll maintain a high picture quality during the
process. You'll be surprised just how professional-looking your results can be
simply by using this very easy to build kit! Powered by 12VDC plugpack.
K 5875 $65 M 9660 12VDC 300mA Plugpack $13.50
12V lnl@[l©gj©tn) Discolight Kit
(See SC Jan/Feb '98) Based on the
original Silicon chip
Discolight, this unit offers
the same features as the
mains version only with
low voltage rails, making it
ideal as a school project or to
add something different to your car at the
next car show or auto salon! Supplied with
an attractive case with pre-punched and
screened front panel and parts to build and
power the unit from 12V DC (halogen
lamps not supplied). Features: • 4 channels J
(20W or 50W halogen lamps) • Forward,
reverse and auto reversing chaser patterns with music modulation •
Simultaneous strobe on all channels • Alternating light patterns • 12V
DC or AC operation • Input from loudspeakers, aux level or mic .
K 5807 Normally $159, NOW $1 09 (Lamps not supplied)
K 5797 Two Tube
Option $18.95
Sound Card Preamp Kit for PCs
Sustain Unit Kit
for Electric Guitars
See SC Apr '98) A sustain
[unit can make your guitar sound
little more "live", by keeping
the volume of a note at a constant
level while the string resonance dies
away. It's one of the most widely
used guitar effects (FX), and this
Simple kit is a fraction of the cost of a
commercial unit! It features adjustable attack and
decay, a defeat switch and standard 6.35mm
input/output jack sockets. Requires a 12V DC
power supply. Supplied short form so you can
build it into a custom case, if required.
K 5539 $27 95
Plugpack to suit M 9664 $14.50
A <lfl r.ufthtin to
onutiorcinl until
FM Stereo
Transmitter Kit
(See SC Oct '88)
Simply connect your^ Q
CD player or any 2? ---
other line level source l
to the mini transmitter! ** VUu "
which converts the 'T n *<*
audio signal to an FM
signal. This FM signal can
then be tuned in via any FM
radio. Great for listening to
your favourite CD while washing the car, mowing
the lawn or doing the vacuuming etc,
without blasting the neighbours.
k„20$34- 95
(See EA August '98)
There ate many audio
aly
ind .
available over the Internet, whlc
utilise the microphone input of
your sound card. It attenuates a
abnormally high signal levels to
acceptable input levels to your
sound card.
Features: • 4 input levels of
attenuation of +20dB to - 40dB • Presents a 1ML2
input impedance, the same as offered by a
professional oscilloscope • Low ohm output
impedance • Limit indicator to alert the user that the A/D converter of
your sound card is in over range • Powered through the +5V outlet on the
joystick port of the sound card (no plugpack required!).
K 2875 $34 9S
Transform your PC into
a fully fledged Audio
Analyser or CRO whilst
protecting your sound
card from damage!
CRO Probe to suit Q 0175 $39.95
AtTRQRlQ
174 Roe St. Perth W.A. 6000
Phone (08) 9328 1599, Fax (08) 9328 3487
MAIL ORDERS C/- P.O. Box 8350
Perth Business Centre, W.A. 6849
(i rm i
VISA
Diners Cfuh
L Intcmalioniii’ J
I Standard Delivery & Packing Charge: $4.00 to 500gms, $5.50 500gms-l kg, $8.00 lkg-5kg.
I Where possible we process your order the day received and despatch via Australia Post.
1 Allow approx 9 days from day you post order to when you receive goods.
I Overnight JeUervice: Up to 3kg is $9.50, 3kg to 5kg is $16.00—We will process your order
I the day received (if placed before 2.00PM WST) and despatched for delivery the next day.
I Country areas please allow an additional 24-48 hours.
1 W A - COUNTRY
I ALBANY
I BUNBURY
I BUSSELTON
I ESPERANCE
Ikalgoorlie
IW^CITV
I BLACKBURN
I CHELTENHAM
I CLAYTON
I COBURG
I CROYDON
I FOOTSCRAY
I PRESTON
COUNTRY
I BALLARAT
I CRANBOURNE
Imildura
BP Electronics •
Leading Edge Hi-Fi
Leading Edge Hi-Fi (08)97216222
Leading Edge (08) 97523522
Esperance Comm. (08) 90713344
Golden Mile Electronics (08) 90215212
QLD-city
(08)98412681 wnnnRmrF
(08)98412077 WOODRIDGE
COUNTRY
Price*! Please note. Normal RRP rates quoted are current selling rates and may vary slightly
from catalogue pricing.(Primarily due to the softening of the A$). Heavy Service: All orders
of 5kgs or more must travel Express Road — Please allow up to 7 days for delivery. $12.00 to
lOkgs. $15.00 over lOkgs. Insurance: As with virtually every other Australian supplier, we
send goods at consignee's risk. Should you require insurance cover against loss or damage
please add $1.00 per $100 of order value (minimum charge $1). When phone ordering please
request "Insurance". Altronics Resellers: Chances are there is an Altronics Reseller right
near you—check our catalogue list or phone us for details of the nearest dealer. Blue Ribbon
Dealers are highlighted with a •. These dealers generally carry a comprehensive range of
Altronic products and kits.
SA - CITY
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MO Vs, battery ampere-hour rating & the Y2K issue
Our topics this month are
mainly centred around
batteries and the Y2K
problem. For example, have
you ever wondered about the
ampere-hour rating of cells
connected in series? We
answer this and other reader
enquiries, and present a
method of testing MOVs
(metal oxide varistors).
’m continuing the discussion on the Y2K
bug this month, with letters from readers
who are actually involved in programming
microcontrollers. Last month I discussed the
issue from a more general aspect, reporting
on the ‘doom and gloom’ the media typically
attaches to the topic.
But what arc the facts? Will aeroplanes
crash? Will there be a global depression? We
can’t address these topics as there are too
many unknowns, but we can look at appli¬
ances and equipment that use an embedded
microcontroller.
The first letter is from a reader employed as
a senior software engineer. He has had consid¬
erable experience with microcontrollers, and
makes the point that cost is the driving factor
on whether an appliance has a date-dependent
operating system:
Your correspondent Nicholas Smith raises
the question of the infamous and over-hyped
Year 2000 bug as it relates to common appli¬
ances, such as a microwave oven. Mv first
electronics job in 1986 involved designing
microcontroller-based systems for white
goods. With 10,000 units per year represent¬
ing a low-volume run, the need for every
resistor (0.7 cents each) was carefully con¬
sidered, as was the need for a real-time
clock (RTC).
The micros were 8048s, with 8049s for big¬
ger jobs; no sign of an RTC, even though
many products had a clock display. We imple¬
mented clocks as a software driven time-of-
day counter, but without a date function, as
adding date-driven code cost too much.
Therein lies the fundamental point — in
the embedded micro world, cost is the main
factor. If it's not absolutely necessary, we
don 7 spend money or time on it.
Over the years 1 have been involved with a
large number of microcontroller-based pro¬
jects. Very few incorporated a ‘built-in ’
RTC, although later micros do offer them.
One of these projects included an external
RTC chip, and it was thoroughly tested to the
late 21st century, well beyond the expected
product lifetime.
Most whitegoods, even though they com¬
monly incorporate a time-of-day clock, don 7
have any date dependence. For that matter,
about the only product that has date depen¬
dence is a VCR. The many micros in cars, TVs,
washing machines, dishwashers, microwaves,
ovens, heaters, even kettles (really!) don’t
know and don 7 care what the date is. At most
they might care about the time of day.
It might be an idea to test your VCRs for
Year 2000 compliance, but for everything
else I wouldn 7 bother. My opinion is the
only applications where the Year 2000 issue
is really important are accounting and other
financial applications, where time differ¬
ences based on dates need to be calculated.
(Geoff Field B.E. Grad I.E.Aust, Chelsea
Heights, Vic)
Thanks Geoff, for acquainting us with the
‘nuts and bolts’ of appliance design and man¬
ufacture, and in particular to the aspect of cost
on the design. However, while whitegoods
might not be a problem, 1 wonder about build¬
ing management systems that use a microcon¬
troller. Are these systems date dependent?
On the other hand, I also wonder just
when programmers started realising that the
year 2000 was just around the comer. I
would expect most programmers would have
started writing code to suit 2000 at least from
the start of the 1990s.
The next letter is also from a reader involved
in microcontroller use and programming.
/ think this Y2K thing is being blown out of
all proportion, like the virus danger some
years ago. At the mere suggestion that basic
appliances might be affected by it, I don 7
know whether to laugh or cry!
For over 14 years 1 have been in the busi¬
ness of designing and programming micro¬
controller systems, mainly for industrial
applications. I have not yet seen a microcon¬
troller chip with an inbuilt clock-calendar
function. As in a PC, if you want that func¬
tion, add an external clock-calendar chip
(CCC) and a battery to run it. But even then,
the CCC is just a peripheral of the micro¬
controller; it is not in charge of proceedings.
The in formation from the CCC is used at the
discretion of the programmer who writes the
microcontroller code.
While some appliances (e.g., VCR,
microwave oven) incorporate a clock, it’s no
guarantee they have a CCC. Generally they
don 7 retain time without mains power, so
it’s likely the time is derived from a mains
interrupt to the microcontroller and a simple
counting routine. And even if a CCC is used,
I’ve not seen an appliance which makes use
of a date function — so why would the date
stop it operating?
And even on a PC, the hysteria has gone
too far. I’m sure many people believe their
old PC will stop when 2000 starts. Again,
why would it? The CCC doesn 7 control the
PC; DOS does. At boot-up, DOS reads the
CCC time and date (with the year stored as
two digits in old machines), and from then
on maintains (updates) the time using its
own crystal oscillator (CPU clock). So if
DOS interprets the year 2000 as 1900 (or
more likely as 1980), so what? DOS doesn 7
care what the date is.
Of course DOS’s interpretation of the day of
the week will be wrong, but that still won 7
cause the PC to crash. Apart from time/date
stamping files saved to disk, DOS simply stores
(and updates) the time/date information, and
passes it on to programs that ask for it.
And that’s where problems begin. If you
can live with the fact that files stored on your
disk will look as though they were stored
before personal computers were widespread,
and if you don 7 mind editing the day/dates
automatically inserted by your wordproces-
sor (or other application), you can still con¬
tinue to use the majority of your programs.
But problems will occur in programs
which use the date for comparisons.
Examples are accounting programs, which
‘age ’ debts, and automatic backup programs
ELECTRONICS Australia, September 1998 67
which make backup decisions based on the
date of disk files compared with the current
(system) date. Programs such as these will
probably not work properly, but these are
minority uses for most home users.
Sure, big institutions and companies with
financial and accounting software systems
will need to do something, and small busi¬
ness and home PC users will need to make a
few checks (or test beforehand — see the BSI
site below). So please, hose down the para¬
noia regarding domestic appliances, before
my sides split!
By the way, for a technical discussion on
the Y2K problem, visit the British Standards
Institute (BSI) site: http://www.bsi.org.uk/
bsi/disc/year2000.html. (Daniel Ford, BE,
MBA, SMIREE, Managing Director,
Advanced Solutions P/L, Beecroft, NSW)
Thanks for this information Daniel, and
for the website address. As you and Geoff
say, date-dependent microcontrollers are
somewhat in the minority. And again it
depends on the code written for the device,
not the actual micro.
So that’s a look at home appliances with a
microcontroller. The message seems to be
‘don’t worry’, at least as far as our two cor¬
respondents are concerned. Now let’s see
what the BSI website has to say.
BSI’s Y2K website
Clearly the BSI is taking the problem seri¬
ously. There’s a wealth of information on
their site, including documents you can
download. I looked at two different pages,
and the following is an edited extract from a
much longer discussion of the problem:
Only when an organisation has analysed
the Y2K problem and its business risks can it
have an accurate picture of the scale of the
task and the time and resources needed to fix
it. Unfortunately, such a picture is typically
more difficult, more expensive and more
draining on resources than any of their esti¬
mates. Or as Caroline Bramley put it; “The
Year 2000 problem is like an onion. The
more layers you peel, the more you find. The
more you find, the more you cry. ”
This is a topic we could explore a lot
more, but I think we’ve got the message. If
you own a company that relies on computer
systems, be it on your own head if you don’t
ensure the system is 2000 compliant. For the
rest of us, check the VCR for compliance.
Lithium rechargeables
In the June issue, a reader (E. De Longis,
Midvale, WA) asked about charging
Panasonic VL2330 vanadium pentoxide
lithium rechargeable batteries. In answer to
the question, Daniel Ford (see above) has
suggested the following:
I don’t know how to charge these batter¬
ies, having only used Sanyo Mn02Li
rechargeables, but I suggest your correspon¬
dent contacts Premier Batteries, phone (02)
9755 1845. This company seems to know
almost everything about almost every type of
battery in common use.
Thanks again, Daniel. These days it’s
almost impossible to keep track of the many
types of rechargeable batteries. However,
charging them is one thing — what about
storing them?
Storing NiCads
The following question is one I’m sure a lot
of readers might have wondered about...
My laptop computer is powered by a
NiCad battery pack. However as I don't use
the laptop all that often (only on trips), and
bearing in mind the NiCad ‘memory effect’,
I wonder what I should do about the battery
pack. Should I regularly recharge it to keep
it in its best condition, or is it OK to leave it
discharged for say six months at a time? The
packs seem to be fully discharged when you
buy them. (Andrew Palmer, Leura NSW)
Sealed NiCads can be stored indefinitely
in a discharged state, or in any state of
charge without significant loss of life.
Ideally they should be stored in a clean, dry
environment below 50°C. There’s no need to
regularly charge them, although if they are
left standing for a long time, you might need
to charge-discharge them several times to
regain their capacity. In this case, the first
charge should be for a 24-hour period
(instead of the usual 14), at the CIO rate
(charge current one-tenth the ampere hour
capacity of the battery).
The only other maintenance is to remove
any crystalline growth from around the seal¬
ing. This growth is not detrimental to the
battery, and can be prevented by smearing
the area with silicone grease.
Now for more on the ampere hour capaci¬
ty of a battery pack.
Tiny tube battery
The next letter takes me to task about my
description of the battery pack in the ‘Tiny
Tube portable lights’ described in the April
and May 1998 issues.
In the tiny tube light articles, you say each
NiCad cell in the battery pack has a capaci¬
ty of 63mAh. You also say in the article "we
made up a pack from 30 of these cells to give
three 12V batteries in parallel, with a total
capacity of around 1.9Ah. ’’
If 30 cells are connected in parallel, you
get a battery with a 1.9Ah capacity, but with
a terminal voltage of 1.2 V. If 10 of these cells
are connected in series, you get a 12V bat¬
tery, but with a capacity of 63mAh.
Connecting three of these in parallel gives a
capacity of 190mAh, not the 1.9Ah you claim.
There’s further inconsistency when you
say the 14-hour charge current to each
68
ELECTRONICS Australia, September 1998
series pack is 40mA, as this implies a capac¬
ity (for 10 cells in series) of600mAh. I would
believe this if the cells were rated at
63OmAh. Incidentally, the volume of these
cells is around that of a 600mAh AA size
NiCad. What is the reality of the situation?
(Ian Darby, email)
Fair questions, Ian. First let’s look at
what’s meant by an ampere-hour rating.
Although it suggests a current rating, it is in
fact an energy or capacity rating. For exam¬
ple, a 63mAh NiCad can deliver 6.3mA for
10 hours, or ignoring other effects, 63mA for
one hour, or 630mA for one tenth of an hour.
The current capability of a cell is
determined by its internal resis¬
tance, which in turn depends on its
construction.
When cells are connected in series
or in parallel, the total stored energy
is the sum of the stored energy in
each cell. Now you might think that
when cells are in series, because the
same current is flowing through
each cell, the chemical action to cre¬
ate the current is the same in each
cell. Not so. If you connect say ten
2V cells in series, with each cell
rated at 1 Ah, you get a lOAh battery
with a terminal voltage of 20V. If
the battery is connected across a 20-
ohm resistor, a current of 1A flows.
However, compared to a single cell,
there’s now 10 times the quantity of
chemicals to produce the current.
Therefore a current of 1A will flow
for 10 hours.
Now to your question about charging the
cells. When 10 by 63mAh cells are in series,
the total capacity is 630mAh. The charge cur¬
rent at the CIO rate (or 14 hour rate) is there¬
fore 63mA, which is what the circuit does
(more or less). The CIO discharge (10-hour
discharge time) is also 63mA. Notice there’s
more energy put into the battery than taken
from it, due to the efficiency of the NiCads.
As for the size of the cells, I have to agree
that their physical size suggests a higher
ampere hour rating. However, they come
from a pack of six cells (in series), with the
pack rated by the manufacturer at 380mAh.
Hence the 63mAh rating for each cell. My
guess is the manufacturer is being very con¬
servative about the rating. And while we’re
talking about the tiny tube lights:
Coax voltage rating
This letter questions the use of the coax
cable used in the prototype to connect the
tiny tube in the strobe-beacon light described
in the May issue.
Thanks for a great project. May I suggest
however that twin coax from a set of head¬
phones is hardly a safe cable for a high volt¬
age circuit. The circuit is labelled Caution -
High Voltage, so why use a cable designed
for a low voltage circuit. You wouldn’t
dream of using this cable in a 240V circuit,
no matter how light the load. Maybe a cau¬
tionary note should be published. (A.J.
Lowe, Bardon, Qld)
Yes, I admit it seems an odd choice of
cable. The peak voltage across the tube is
around 380V, much the same as the peak
voltage from a 240V AC source. However
the important difference between a 240V
power outlet and the output of the tiny tube
inverter is the current capability. The cable
Fig. 1
to
loaded
inverter
(Vpk = 400V)
Fig.1: Suggested setup for testing a 275V
MOV.
used in the prototype is thin twin coax, with
each cable individually insulated with a rub¬
ber coating. The earth braid surrounding
each cable is not used.
This means there’s at least 0.5mm of rubber
insulation between each cable. The dielectric
strength of rubber is somewhere between 10
and 20 times higher than air, or around
30kV/mm. This means, at a conservative esti¬
mate, at least 15kV is needed between the
cables to cause the insulation to break down.
Being a construction project, we assume
readers will choose cables to suit the appli¬
cation of a project. If you intend using the
tiny tube light in situations where the cable
could be subjected to physical abuse or
strain, then clearly you should use cable with
heavier insulation. In normal use, this is not
a problem. However, thank you Mr Lowe,
for raising the point. Yes, as with any high
voltage circuit, caution is essential!
MOV rating
A MOV or metal oxide varistor is often
called a voltage suppressor. Although
they’re used extensively, cost less than $2
and are readily available, they are still an
obscure device to many people. This letter
asks questions about MO Vs that others
might have wondered about:
I use MOVs to suppress the back EMF
across a relay coil. I also use them between
phase and neutral to protect equipment from
voltage transients. MOVs are generally given
a rating in joules, which I believe means the
device has a limited life based on this rating.
How can I test a MOV without using an over¬
voltage source and a CRO? Commercial
surge protectors often have an in-built alarm
to indicate the device needs replac¬
ing, but I suspect this is simply a
fuse-type indicator. (Kim Pederson,
Port Moresby, PNG)
A typical mains-rated MOV has a
voltage rating of 275V, and an ener¬
gy rating of between 20 and 40J.
One joule per second is a power of
one watt, so a 40J device can handle
40W of power for one second.
Extrapolating backwards, the same
device can handle 400W for 0.1s,
and 4kW for 10ms, which is the
duration of half a cycle of mains
power. That is, the allowable fault
current for 10ms is around 14A, usu¬
ally enough to blow a fuse.
Unfortunately, testing a MOV
takes longer than a few seconds,
which means using a test current of a
few milliamps. A test method I’ve
used is shown in Fig.l. If the MOV
is working, the AC voltmeter will
indicate a voltage proportional to the current
flowing in the resistor. Naturally you should
First make sure the MOV is not a short-cir¬
cuit. I don’t know of any test method that
doesn’t involve a suitable voltage source.
What??
This month’s question comes from Jim
Lawler, of Geilston Bay in Tasmania. The
answer to the question can be calculated, but
even trying to guess it should prove interest¬
ing. It’s about the range of length measure¬
ments we need to perform.
Consider the smallest distance and the
largest distance man needs to measure. What
is the difference in centimetres (expressed as
a power of 10) between the two?
Answer to August’s What
The answer for circuit (a) is 300Q, which is
obvious as the resistors are in series. Circuit
(b) also poses little difficulty, as the jumper
shorts out two resistors, leaving a total resis¬
tance of 100£L Circuit (c) has a resistance of
33.333Q, as although not obvious, the three
resistors are in parallel. It often helps to
redraw the circuit! ❖
ELECTRONICS Australia, September 1998
69
Vintage Radio
Two Valve Sets — 1927 to the pre octal era
1927 can be regarded as the year that all-electric sets were
introduced. As the rectifier was at first not counted as a
‘valve’, a 2/3-valve electric set was considered as a two-valver.
So from 1927 on, there’s plenty to talk about when it comes to
‘two valve’ receivers...
T here are no definitive dates for the intro¬
duction of new ideas etc. Rather a date is
claimed that is generally acknowledged
to be when the new ideas began to penetrate
the market. So, for 1927, 1928 and perhaps
1929 and 1930 as well, there were still many
battery operated two-triode transformer cou¬
pled radios being built by enthusiasts.
The electric sets began to make their
presence in about 1927. In the early years
they were all-triode affairs, comprising usu¬
ally around six stages plus a rectifier. When
used with the then-new balanced amature
or cone speakers, they can to this day give
a reasonable acount of themselves.
Did we have battery powered all triode
two-valvers capable of loudspeaker opera¬
tion? There was one particular English
radio, made by Kolster-Brandes Ltd and
marketed in conjunction with cigarette
manufacturer Godfrey Phillips. Evidently,
if you collected 500 vouchers from the 10-
packs of ‘BDV’ cigarettes, you got the
radio for free! Given that in 1930 there
were supposedly no ills associated with cig¬
arette smoking, for the sum of £12/10/- you
got to smoke your 5000 durries and got a
free wireless. Not a bad deal, really!
This dinkie little set is illustrated in Fig.l.
It is fully enclosed in a bakelite case, a 7-1/4”
cube, uses rather surprisingly French ‘Fotos’
triodes, and requires external batteries.
In this country, the ‘Crosley’ model 51, a
two-valver, was being offered for as little as
£5/10/- complete, and was said to work a
loudspeaker. An advert is shown in Fig.2. It
must be stressed that by 1928 or so, many
of the stations had increased their transmis¬
sion power to up to 5000 watts in some
cases, with many being in the 1000-2000W
range. Compared with the 300 - 500W lev¬
els of two or three years earlier, the increase
Fig.l: The English made Kolster-Brandes
two-valver of 1930 came free with 500
cigarette coupons, in an offer from the
Godfrey Phillips tobacco company.
in transmitted power no doubt contributed
to the ability of little sets such as the
Crosley 51 to drive a loudspeaker.
One of the locally made all triode two-
valvers was the ‘Astor’ Electric Two of
1930, and Stromberg Carlson also released
an all-triode electric model in a most pre¬
tentious cabinet, with an equally preten¬
tious ‘quarter-acre’ chassis.
The Philips 2516
The Philips 2516 came pretty close to a two-
triode loudspeaker radio. It is a triode regen¬
erative detector, transformer coupled to an
output stage using the new ‘penthode’ (as
they were first called). When used with a
long wire antenna and a sensitive Philips
speaker, loudspeaker results were indeed
possible. It must be stated that the Philips
‘Sevenette’ and ‘PCJJ’ speakers were very
good for their times, and sound quite accept¬
able even today.
Fig. 3: Inside the Philips 2516, an all-electric ‘two valver '.
Outside, it looked very similar to their well-known battery
eliminators of the day — deceiving many would-be collectors.
70 ELECTRONICS Australia, September 1998
by Roger Johnson
The inside of a Philips 2516 is illustrated
in Fig.3. The circuit holds no surprises, and
consists of an E415 or similar triode, a
B443 output and a 506 rectifier, all with
European bases.
Unfortunately, this set has all the hall¬
marks of ‘Philip’s fillips’ and is con¬
structed in the three dimensional mode.
There is a four-position antenna connec¬
tion comprising a link with a moulded
bakelite handle, and two rows
of four sockets. Position one
uses the dubious practice of
using the mains cord as an
antenna, in that the mains is
connected to the antenna termi¬
nal of the coil via a mica capac¬
itor of about 500pF. In the other
three settings, an external anten¬
na is connected by one of the
three small value capacitors to
the coil. A two-position switch
selects a tuning range of either
2000-800kHz or 1100-430kHz.
Between the tuned circuit and
the grid capacitor is what can
only be described as a grid stop¬
per of 350 ohms. Just what pur¬
pose it serves is debatable.
(Surely it couldn’t be there to
prevent parasitic oscillations?)
At the rear of the set are two
sockets marked ‘G’. These are
obviously for gramophone input.
One connection is direct to the
radios, these sets were known to be con¬
fused with the Philips ‘B’ and ‘C’ battery
eliminators, and as a result were often over¬
looked at auction sales. Prudent collectors
recognised them immediately, and because
of the lack of interest, purchased them very
cheaply indeed!
For all the unusual layout and wiring
practices, the 2516 is beautifully made, is
well designed, and is a good performer.
‘Screen grid’ valves
By about 1928 the new tetrode type UY224
was released, and made its way to this coun¬
try by about 1929, appearing in the contem-
pory magazines first by way of introduction
and then in illustrative circuits. A similar
story applies to the Philips E442, and the bat¬
tery types that first appeared such as the
American UX222 (which has a 3.3V fila¬
ment, incidentally), the Marconi
S625 and Philips A442, and a
host of other British types.
Together with the newer output
pentodes B443, C443, and type
247, a higher gain receiver was
now possible.
The screen grid valves were
unsuitable for transformer cou¬
pling. This is a characteristic of
high impedance valves, be they
high gain triodes or pentodes.
Particularly when using the
UY224, the standard proce¬
dure was to use ‘impedance
coupling’ (otherwise known
as choke coupling), from the
224 to the output stage.
Basically, the anode load
resistance of usually 250k
was replaced by an an iron x
cored choke of about 10 hen-
rys (or greater) and having a
DC resistance of perhaps only
3k or so.
BIGGEST VALUE BY FAR
CROSLEY” 2-valve Radio
A splendid double circuit receiver, extremely
selective, it works all local stations at speaker
strength.
The “Crosley” compares more than
favorably with sets twice the price. £ PJ* / ^ f
Complete with valves, batteries, 3L O / X II /
aerial and phones. f '
OR EASY TERMS.
grid, and the other is a point on
the negative supply line at -4.7V. The com¬
bined decoupling resistor, grid leak and
voltage dividing resistors present an input
impedance of 2.2 megohms, across which
is a bias of -4.2V. When connected to a
comparatively low DC resistance magnetic
pick-up, this bias will now appear at the
grid of the E415, which represents about
the right voltage for the anode potential of
70 volts for maximum class A operation. A
very clever piece of circuitry...
The detector is of the ‘leaky grid’ type,
and reaction is controlled by a vario-cou-
pler. As far as the rest of the circuit is con¬
cerned, it is conventional. HT filtering is in
the negative line via a two-section choke.
There is decoupling just about everywhere
because of the low value filter capacitors
all paper types, of only luF. There is no
volume control.
The cabinet of this set looks rather famil¬
iar. In the early days of collecting vintage
Fig.2: The Crosley model 51, a battery
two-valver advertised in The Listener In
for 15 Feb 1928. As you can see from the
circuit below it was very basic.
EVATCO
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12AX7WA JAN Philips ECG Mil Spec $ 14.00
12AX7WA Sovtek. $ 10.00
300B Sovtek Dual Point matched $125.00
807 AWV Australia. $ 19.00
E82CC/6189 Siemens Germany . $ 20.00
EL34/6CA7 Sovtek or Svetlana Matched
. $ 26.00
EL84/6BQ5 Sovtek Matched. $ 17.00
GE Tube data Manual 1973 473 pages
. $ 26.00
TUBE DATA 3.5 Dos Disk 27,000 tubes$ 53.00
SSAE DL size for CATALOGUE
ELECTRONIC VALVE X TIRE COMPANY
PO BOX 381 Chadstone Centre VIC 3148
Tel/Fax (03) 9571 1160 Mobile 0411 856 171
Email: evatco ©mira.net
ELECTRONICS Australia, September 1998
71
READER INFO NO. 24
Vintage Radio
i'OJHHWiO
ClL *
A ^WjM.
D 5? P247 /?/, /QOOOsi (S&ecfmry)
R 2 t MC(jn- . /?3, 150,000jt. foqocc -n..
lOqoooj*-. CiA t ’inf C^Z 'O/nf
C*d. OOOInf C$ 000//*}-. C 5 ,b fnft/ec/’ro/yFc,
Sp ea I er //eld z too si fyp ed&t zoo s^
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noDfL 22
Fig.4: Very typical of the early 1930s two-valve electric sets is the Healing model 22
circuit shown here. Regenerative detector D drives output stage P directly.
This was done to overcome the problems
of transformer coupling, yet still maintain a
substantial anode potential by virtue of the
reduced DC voltage drop across the wind¬
ing. The impedance of the choke at audio
frequencies, which represents the true plate
load, is up around 100k ohms. The old ‘24A
simply lost too much gain with the reduced
anode voltage caused by a conventional
resistor as the plate load...
With the later series of 57/2A5 or 6C6/42
combinations the problem was not so bad,
and the standard form of R-C coupling was
the norm.
Commercial regen sets
There are absolutely no shortage of commer¬
cial two-valve electric sets based on a regen¬
erative detector, either in the literature or
amongst collectors. Many manufacturers
offered them. ‘Eclipse’ chassis in particular
were offered under different labels for the
various department stores’ own brand budget
priced sets. For most sets the valve combina¬
tions were a 224A driving a 47, or various
Philips types such as E452 and E443H, fol¬
lowed by the later combinations of 57/2A5
and 6C6/42.
Properly designed, these sets could per¬
form quite well. However, there was little
point in offering a set for half the cost of a
superhet that performed better than half as
well as a superhet, now was there? Some of
the tricks used by the manufacturers were
reduced screen voltage on the detector
stage, thereby reducing the stage gain, and
over bias on the output stage. In this stage
this had two effects; it limited the plate cur¬
rent and hence the power delivered to the
speaker, and it reduced the sensitivity!
The coils for these sets were invariably of
the solenoid type, wound on either an
impregnated cardboard or bakclite former
and using solid enamelled wire of about 32
SWG. Some of the very early sets used cot¬
ton covered wire. The antenna connection
was either via a tap towards the earthy end
of the coil, or a small coil wound on a bob¬
bin placed inside the coil former. The aeri¬
al coil primary invariably had one or more
taps. The antenna also tended to be gener¬
ously coupled to the tuning circuit, making
station separation of close stations very dif¬
ficult — hence the choice of antenna con¬
nection. In fairness, though, in the early
1930s there simply weren’t as many sta¬
tions as there are today, and they were a lit¬
tle further apart.
Here in Adelaide, the test of a good sin-
gle-tuned-circuit regenerative detector is
to separate 5DN on 1323kHz and 5AA on
1397kHz. Not many of them pass the test.
The only way to achieve it is to reduce
the antenna coupling. However, many
circuits had the volume control, which
was a 1000 or 2500 ohm pot, simply
shunted directly across the primary wind¬
ing, with the wiper connected to earth.
Removing turns from the primary then
made the volume control more difficult
and it also tended to dampen the tuned
circuit — making tuning more difficult.
In cases like this, the antenna coupling
can be reduced by experimenting with a
small value fixed capacitor in series with the
antenna and the antenna winding of the coil.
However performance at the low frequency
end of the coil drops off appreciably...
Reducing the antenna coupling also
reduces the gain. One sure way to improve
the gain is to operate the detector screen at
maximum value. This means modifying the
circuit by substituting a screen dropping
resistor with one that is different to the orig¬
inal value. Such modifications are the sub¬
ject of vigorous debate between the purists
and the pragmatists. One neat conscience¬
saving ploy is to make the receiver work in
a practical manner, whilst kidding oneself
that one ‘can always change it back to orig¬
inal if one chooses’.
Shown in Fig.4 is the circuit for a
Healing model 22 of 1932 vintage, which
has most of the features described and nice¬
ly illustrates the piont. The screen voltage
would be lower than maximum rating.
When was the rectifier considered to be a
‘valve’? After all, it’s only a dumb old twin
diode; it doesn’t really Jo anything!
Well, around the mid 1930s some slick
fancy-pants salesman probably realised that
since it was made of glass, you could plug
it in, and it glowed in the dark like the oth¬
ers, then it was a valve. Suddenly, a ‘two
valve’ set became a ‘three valve’ set, with
all the added advantages a third valve
offers. Ho hum....
Multiple valves
In the pre-octal era came the type 53 and the
later 6A6 valves. Although these were
designed as a class B output valve, there
were hobbyist circuits that used them as a tri-
ode regenerative detector with an R-C cou¬
pled audio and thence to a pentode output.
Good results were claimed.
The other multiple valve of note was the
6F7, which was originally intended as a
mixer oscillator. This tube has separate
pentode and triode units within the one
envelope, sharing a common cathode. It
was used for a variety of purposes other
than its original intention.
Because of the pentode section, the 6F7
could be used as a RF amplifier and regen¬
erative detector triode, and then R-C cou¬
pled to an output stage. Again, good results
were claimed, because of the increased
selectivity. ❖
ELECTRONICS Australia, September 1998
72
‘Front End’ for PC
Audio Recording
(Continued from page 49)
a template for drilling it too. Here the four
3mm holes only need de-burring. You might
also want to solder the end of a short length
of hookup wire to the copper laminate, for
convenient connection to the PCB earth
when they’re in situ.
It should now be possible to mount the
PCB assembly inside the case bottom. I used
12mm-long 3mm countersink head screws,
passing through the case bottom and then
through the shield plate before star lock-
washers and nuts were fitted (mainly to act as
short spacers for the PCB). Then, after
checking that all of the component leads
were trimmed short under the PCB, to pre¬
vent shorts, the PCB was fitted to the remain¬
ing screw ends and a further lockwasher and
nut added to each screw to fasten it in place.
After mounting all of the controls to the
front panel and the connectors to the rear
panel, you’re then ready for the final stage:
adding all of the off-board wiring, between
the PCB and the controls and connectors.
This is fairly straightforward, but take it
easily and carefully to avoid errors.
Note that shielded audio cable should be
used for the wiring to the microphone jack
and magnetic pickup input sockets, at the
very least. You may also want to use this
cable for the wiring to the Tape/Line input
sockets, and perhaps that to SW1, RV1 and
RV2 as well — to minimise susceptibility to
noise and hum, etc. It’s probably not neces¬
sary to shield the wiring to SW2, RV3, RV4
and the output connectors, though, as the sig¬
nal levels here are higher and the impedance
levels lower. There’s also no need to shield
the wiring to the power LED, of course.
By the way, don’t forget to solder a lead to
the metal bodies of each of the pots on the front
panel, with its ‘other end’ connected to signal
earth — say via the earth lead from the LED.
This should ensure good earthing of the con¬
trol cases and front panel, and allow them to
act as a shield plate above the PCB assembly.
With this final wiring done, your
Recording Front End should be just about
complete. As there’s no actual setting-up
required, little should remain except assem¬
bly of the case, and connecting it up to your
PC for a trial run.
By the way, I’ve discovered (largely the
hard way) that there are a few tricks to get¬
ting the best results when you’re using the
RFE with a PC and sound card for making
digital audio recordings and transcriptions.
In a follow-up article, I’ll try to pass on
some some suggestions and helpful tips on
putting it to use. ❖
Subscribe to
Electronics Australia
and save $$$$
See page 82 for details.
Valve Electronics
Pty Ltd ACN 001944369
Overhaul custom work &
restoration: all types of valve
amplifiers radios & equipment.
New, NOS & S/H parts for
sale. Catalogue on request.
P/0 Box 467 Newtown NSW 2042
Ph 02 9557 2212 Car 019449311
Fax 02 9516 3981
e-mail valve1@ozemail.com.au
ELECTRONICS Australia, September 1998
73
READER INFO NO. 26 READER INFO NO. 25
Computer Clinic
Creating your own Windows program with the CGI...
L ast month, after answering Mr Healy’s
query about Windows programming, it
struck me that there is a way to create a
Windows program without having to shell
out for an expensive, often hard to drive,
programming language. There is a way to
use your own favourite DOS language, be it
Pascal, C, a batch file, or (for the strong of
stomach) BASIC to create a perfectly good
Win95-looking app without ever having to
deal with the mind-numbing ugliness of
Windows system calls. What’s more, you
get to use an interface that’s probably more
widely used than any other application: the
web browser! That’s right, this month I’m
taking you on a lightning tour through the
weird world of the CGI.
Before I go any further. I’d just like to
point out that this isn’t the most eminently
practical approach to things (or very easy to
distribute), as the setup is somewhat fragile
and takes a fair amount of overhead to sup¬
port it. Also, the only controls you can use
are radio buttons, check boxes, text boxes
and drop-down lists. No menus, no message
boxes and no multiple windows. It is fun to
work with, however, and you will learn a lot
about what goes on whenever you use a
search engine, see a hit counter or look
through a webcam.
Are you being served?
Apart from a web browser, all you need is an
HTTP server. HTTP servers (also known as
web servers) are the programs that make the
World Wide Web possible. They pick up
HTTP requests from the network and send
the appropriate web page back to the com¬
puter requesting it. As well as simply send¬
ing HTML files and pictures, they have
another major function that has made the
web what it is today: the Common Gateway
Interface (CGI).
The CGI is a mechanism that allows the
server to run an external program, and send
that program’s output back to the user as a
web page. This is how search engines work.
You type your query into a form on the main
page, and the web server takes the form and
hands it to the search software, which spits
back the results of your query, nicely for¬
matted in HTML. The web server then sends
this output back to you, making it look as
though it already had a whole web page
devoted to your query just sitting there.
There are lots of cheap or free HTTP
server programs out there. The one I use is
OmniHTTP vl.01, available from
http://www.omnicron.ab.ca/httpd/index.
html. It’s small, it works, and it’s free.
Once you run the install program, every¬
thing is ready to go; just point your brows¬
er at http://l 27.0.0.1, and you should see an
FTP-style directory listing. Click on
Default.htm, and you should see the intro¬
duction page.
There is one minor inconvenience with
Microsoft Internet Explorer 4: If you are
working offline and try to access the local
server, IE4 will quite unnecessarily try to
connect you to your ISP. If this happens,
cancel the ‘Connect to:’ requester, go to the
File menu, deselect ‘Work Offline’, and try
again. Netscape users don’t get this problem;
but then again, they have to use Netscape,
which is almost as annoying.
Local hero
If you’re thinking T can’t do this. I’m not on
the net’, then fear not. You don’t need a web
site, a connection to the internet, a network
card or even a modem. The clever people
who designed TCP/IP (the network protocol
used on the internet) reserved the IP address
127.0.0.1 as a loopback address. This means,
in effect, that data requests sent to 127.0.0.1
don’t go through the network card or modem,
but go straight to your HTTP server instead.
If you have no connection to the internet at
all, then you will need to make sure that
TCP/IP is installed on your computer. To
check whether you have it, go to Control
panel|Network, and look at the list that
appears. If you don’t see TCP/IP anywhere,
click Add, Protocol, Microsoft, TCP/IP, Ok.
You’ll be prompted to insert your Win95
CD, and to restart your computer.
How to do it
The actual implementation of CGI program¬
ming is very simple. You will need to make
an HTML page, using one of the many
HTML editors out there such as HoTMetaL
or Microsoft FrontPage. (If you are feeling
adventurous, stick with good old Notepad.
You get a lot more control over the finished
result, and a lot more kudos as well.)
The web page should contain a hypertext
link to your CGI program, either in the form
of a standard <A HREF> link or a form. All
you do is put your program into the CGI-
BIN subdirectory of your web server’s direc-
<HTMLXHEADXTITLE>Demo f orm</TITLE></HEAD>
<BODY BACKGROUND="http : //127.0.0.1/images/bg . gif"> pj a 1
<CENTER>
<Hl>Demo form</Hl>
<HR>
<FORM ACTION="http : //127.0.0.1/cgi-bin/someprog.pi" METHOD=GET>
<TABLE WIDTH=80%XTR VALIGN=TOP>
<TDXH3>First name : </h3><SELECT NAME="FirstName">
<OPTION>Fred</OPTION>
<OPTION>Joe</OPTION>
<OPTION>Harry</OPTION>
</SELECTX/TD>
<TDXH3>Last name : </H3><INPUT NAME="LastName" TYPE=TEXTX/TD>
<TD ALIGN=RIGHTXH3>Pet owned :</H3>
Dog: <INPUT TYPE=RADIO NAME="Pet" VALUE="Dog"XBR>
Frog: <INPUT TYPE=RADIO NAME="Pet" VALUE="Frog"XBR>
Pig: <INPUT TYPE=RADIO NAME="Pet" VALUE="Pig"XBR>
Chicken: <INPUT TYPE=RADIO NAME="Pet " VALUE="Chicken" CHECKEDXBR>
</TRX/TABLE>
</FORM>
•</CENTER>
</BODY>
</HTML>
74
ELECTRONICS Australia, September 1998
by Jean-Baptiste Cattley
@echo off
printf "Content-type: text/html"
Fig.3
printf ""
printf "<HTMLXHEAD><TITLE>CGI slideshow batch file demo</TITLEx/HEAD>"
printf "<BODY BGCOLOR=*#F0F080'>"
printf "<CENTER><Hl>Images in c:\win95</HlXHR>"
for i%s in (c:\win95\* .bmp) do printf "%%s:<BRXIMG SRC= * %%s ' XBRXBR>"
printf "</CENTERXHRX/BODYX/HTML>"
tory, and provide a link to it in your web
page. Clicking the link will execute the pro¬
gram, which will in turn produce a new page
that will display on your browser.
If the program is self-contained (i.e. it
doesn’t require any input from the user),
you can simply link to the program as
though it were another web page, for
example: <A HREF-’http://127.0.0.1/cgi-
bin/mycgi.exe”> Run the CGI app! </A>.
The program simply prints the informa¬
tion to its standard output, using printf(),
PRINT, or however your favourite lan¬
guage normally produces text.
If your program needs information
from the user, things get a little more
complicated. You need to send the infor¬
mation to the program using the HTML
<FORM> element (used to create check
boxes, text areas, etc). The <FORM> ele¬
ment has two major attributes: ACTION,
containing the link to the CGI program
(as above), and METHOD, which con¬
trols how the information is to be sent. I’ll
be using METHOD=GET in this article,
which puts the contents of the form into the
QUERY STRING environment variable.
(The other option is METHOD=POST,
which makes the form data available on the
program’s standard input. More flexible, but
not as simple.)
A complete HTML form, then, might look
something like Fig.l. The INPUT sub-ele¬
ments are used to create the actual controls on
the form. The TYPE and VALUE attributes
define the controls’ appearance, but what
we’re interested in the moment is the NAME
attribute. When the form is submitted, the
form data is encoded in name=value pairs
separated by ampersands, so the form in Fig.l
would produce FirstName=Fred&Last
Name=Bloggins&Pet=Chicken. This string
can then be read by your program (using
getenv() or equivalent) and the information
extracted.
CGI in action
Once your program has digested the data, it
needs to return the program’s output to the
browser in HTML format. First, though, it
must tell the web server that it is sending a
web page. This is done by outputting
“Content-type: text/html” and one blank line
before sending the rest of the page.
That accomplished, all it has to do is to
dress the output up in HTML format. This can
B33ES
E*» E<* lio
O O (2
S3 &
TioTxl l
ml
E
OArg a w ti v cg «•**
Using the CGI for trivial purposes
Fig.2: A very simple CGI-based program in
action. It does simple maths with two
selected numbers.
Fig.3 shows another little demo that 1
knocked together; this one produces a simple
slide show of all files in a given directory. This
wouldn’t be terribly interesting if it weren’t for
the fact that it was produced with an ordinary
DOS batch file. This would have been a
more or less trivial task, except that DOS’
ECHO command can’t handle the angle
brackets used in HTML, and tries to treat
them as redirection characters. Putting the
string to be printed in quotes solves the
redirection problem, but causes the quota¬
tion marks to be printed as well, dotting
redundant punctuation all over the page...
To get around this, I wrote a tiny C util¬
ity that does the job properly, and even
expands environment variables. The only
drawback is that you have to replace any
quotation marks that you actually do
want printed (around a link, for example)
with backticks ('). Once again this utility
is available online, as are all the programs
I write for this column.
Mind your language
be as simple as sticking “<HTML><BODY>”
on the front, and “</BODY></HTML>” on
the end, but you can get as fancy as you like,
with images, tables, more forms, or even
frames if you want.
You can see a decidedly non-fancy example
in Fig.2. This little program, written in C,
takes two numbers, and adds, subtracts,
divides or multiplies them together, and dis¬
plays the result in graphical format. This is
achieved by going through the result, digit by
digit, and printing an HTML <IMG> tag for a
GIF of that digit. (I created the images at about
four in the morning, so please excuse the slop¬
py mousewriting.) It also prints its own calling
form at the top of the page, so you can run it
again without having to go back.
The hardest part of writing the whole pro¬
gram was the string handling for extracting
the numbers from the POST string. Once that
was done, everything was plain sailing. The
source is a little long to print here, but it’s
available on the EA BBS and web site, along
with the images and executable version.
The upshot of all this, then, is that you can use
virtually any language you like to write your
program. It shouldn’t take very much work at
all to adapt an existing program (assuming you
have the source code, of course!) to the CGI.
The only limitations are that program’s output
must be redirectable to a file, and that it exits to
DOS after completion.
This does put a bit of a crimp in QBASIC,
which uses direct screen output and returns
to the editor after running the program.
There are ways round this, however. If you
say OPEN “CONS:” FOR OUTPUT AS #1,
you can just use PRINT #1 for outputting
text, avoiding the direct-video text output.
As for the retuming-to-editor problem, you
can use one of the many shareware BASIC
compilers out there to compile your program
as an EXE that returns straight to DOS.
For the C programmers among you, there
are a number of CGI libraries out there that
make CGI programming a lot nicer than the
quick hack that I wrote. One such library is
Eric E. Kim’s cgihtml package, available from
http://www.eekim.com/soft\vare/cgihtml. ♦>
ELECTRONICS Australia, September 1998 75
Electronics Australia is one of the longest-run¬
ning technical magazines in the world. We started
as Wireless Weekly \n August 1922 and became
Radio and Hobbies in Australia in April 1939. The
title was changed to Radio, Television and
Hobbies in February 1955 and finally, to
Electronics Australia in April 1965. Here’s some
interesting items from past issues:
SO years ago
September 1948
Waveforms made to Order: A new electronic circuit for med¬
ical diagnosis and research will produce any desired waveform
when its shape is cut from cardboard and placed between a cath¬
ode ray tube and a photomultiplier tube. Wave characteristics
become available which are difficult or impossible by means of
ordinary electronic circuits.
The device is designed to provide either single or repetitive
stimuli, derived from a simple silhouette easily cut by following
any desired curve drawn on cardboard. The mask so obtained is
placed in contact with the screen of a CRT having a short-persis¬
tence phosphor, with the CRT trace spread vertically into a thin
line by an RF oscillator. The line is caused to move from left to
right by a relaxation oscillator, which sets the waveform fre¬
quency. An RCA 931-A or similar photomultiplier tube is placed
about eight inches from the face of the CRT and mask. The
amount of light which falls on the phototube is a function of the
length of line which it sees at any instant, and this is determined
by the shape of the mask. The output of the tube is approximate¬
ly 10 volts with a 750V power supply and a 50k£2 load resistor.
2$ years ago
September 1973
Darwin-Mount Isa Link nears Completion: Spanning 1000
miles of desert between Darwin and Mount Isa, Australia’s new
$10 million microwave link is nearing completion. Consisting of
43 repeater stations, some up to 250ft high, the new system will
enable Darwin to dial direct to almost anywhere in Australia.
The system will have an initial capacity of 1200 channels to
provide telephone, telegraph and data communications facilities
for a vast area of Australia’s north, and will link Darwin into the
national subscriber trunk dialling network.
Low cost Computer Graphics Terminal: A high performance
minicomputer based graphics terminal priced from approximate¬
ly $10,000 has been announced by Digital Equipment Australia.
The GT40 intelligent terminal links Digital’s PDP-11/10 mini¬
computer to a specially designed, hard-wired display processor
and a 12-inch diagonal oscilloscope. A light pen, full ASCII key¬
board and character set, 31 special mathematical and scientific
symbols, and an APO approved serial communications interface
are standard features of the GT40.
The low-cost terminal may be used either as a stand-alone
graphics system or as a remote terminal interacting with various
types of host computers. ♦>
Crossword
Across
I Shape of an oscillation. (8)
5 Rapid fluctuation of
a picture. (6)
10 Again inserts a cassette,
cartridge etc. (7)
II The initial phase. (7)
12 Heavy metal. (4)
13 Detect. (5)
14 Brief signalling tones. (4)
17 Winding machine. (5)
18 Elementary gas. (6)
21 Pertaining to certain iron
compounds. (6)
22 Desktop hardware item. (5)
26 Built-in operating system. (4)
27 Plural of vacuum. (5)
28 Band instrument. (4)
31 Valve. (7)
32 State of non-transmission of
radiated energy. (7)
33 Co-inventor of the Geiger
counter. (6)
34 Inventor of the famous H4
chronometer, John.
(1693-1776). (8)
Down
1 Periodic variation of a
sound’s pitch. (6)
2 Name of effect where stress
changes magnetism. (7)
3 A character that signals
some special condition. (4)
4 A list for duty periods. (6)
6 Radio engineers’
organisation. (1,1,1,1)
7 Isotope of hydrogen. (7)
8 Store for fixed amount
of digital information. (8)
9 Amplifying device. (7)
15 Written piece of music. (5)
16 Small power indicator:
the .... light. (5)
19 Popular brand of diskette. (8)
20 Illegally copied for
commercial use. (7)
21 View facing forepart. (7)
23 Acquires knowledge,
systematically. (7)
24 Visible atmospheric
phenomenon. (6)
25 Elementary particle. (6)
29 Region of a magnet. (4)
30 Organic filament. (4) ❖
August’s solution:
HBHBmnnH hbbbiib
BBSS BilSHQ EIJDB
nmEClBBBE
BBBSQSEnSEHBnDE
E
mi
76
ELECTRONICS Australia, September 1998
enough
Picture courtesy Apple Computer Inc., Gary Parker
Electronics Australia's
Professional
Electronics
Intel announces Pentium II
'Xeon' processor for
servers & workstations
Texas Instruments sells its
DRAM business tn Micrnn
Designer's guide tn charging
Li-Ion Batteries:
: .
gpih.
mm
Semiconductor distributor Fastron Technologies has moved to these
impressive new premises at 25 Kingsley Close , Rowville 3178; phone
(03) 9763 5155.
Compaq closing Digital
assy plant in Sydney
Motorola to mass
produce new ‘biochips’
Rapid advances in medicine, health care and
agriculture are expected from a joint-
research project announced by Motorola,
Packard Instrument Company and the US
Department of Energy’s Argonne National
Laboratory. The project, which aims at com¬
mercializing and marketing advanced
biochips and related analytical technologies,
is expected to make the process of decoding
genes, human or otherwise, 1000 times
faster than with current technologies.
Motorola will develop manufacturing
processes to mass produce the biochips, and
Packard will develop and manufacture the
analytical instruments to process and ana¬
lyze them. Argonne’s contribution, in con¬
junction with its Moscow research partner
the Russian Academy of Science’s
Engelhardt Institute of Molecular Biology, is
intellectual property in the form of 19 inven¬
tions related to biological microchips.
Motorola and Packard will contribute a total
of US$19 million over five years to support
the joint-research agreement, making it one of
the largest biotechnology joint-research agree¬
ments ever signed by a US Department of
Energy laboratory. Argonne’s 19 inventions,
which have been licensed exclusively to
Motorola and Packard, are the result of more
than $10 million in research support since
1994 by the US Department of Energy, the
Defense Advanced Research Projects Agency,
the Russian Academy of Sciences, and the
Russian Human Genome Program.
Like computer chips, which perform millions
of mathematical operations a second, biochips
can perform thousands of biological reactions,
such as decoding genes, in a few seconds.
The Argonne/Engelhardt biochips employ
a novel ‘micro-gel’ technology in which as
many as 10,000 micro-structures are mount¬
ed on a single glass surface about the size of
a microscopic slide.
Each micro-gel is like a micro-test tube, in
which chemical compounds can be tested
against biological targets to provide answers
to questions about DNA sequence, genetic
variation, gene expression, protein interac¬
tion and immune response.
In addition to being faster than conven¬
tional gene sequencing methods, these
biochips provide a three-dimensional plat¬
form that allows greater sensitivity and accu¬
racy in assaying proteins, RNA and DNA.
As part of the global rationalisation follow¬
ing the acquisition of Digital Equipment by
Compaq Computer, Digital’s assembly plant
in the Sydney suburb of Lane Cove is being
closed. Its operations will be incorporated
into Compaq’s existing configuration centre
in Rydalmere, the company has announced.
Compaq Australia’s MD Ian Penman,
who will be running the combined operation
in Australia, has announced that some 300-
400 jobs will be lost in Australia as part of
the merger.
Voluntary recall of Tek’s
TDS210& TDS220
Tektronix is voluntarily recalling its model
TDS210 and TDS220 oscilloscopes after
determining that certain incorrect use of the
product could cause the ground connection
to fail. Although there have been reports of
situations in which the ground lead on the
oscilloscope has opened when the products
were incorrectly used, the company is not
aware of any injuries to users. However, a
failure of the ground connection does have
the potential of exposing the user to the risk
of serious personal injury or death.
If a user incorrectly connects a probe
ground lead to a voltage source, or incorrect¬
ly touches the ground ring near the probe tip
to a voltage source, a circuit board trace in
the oscilloscope’s electrical ground path may
open. Once this occurs, the product may
appear to function normally; however, the
unit is no longer properly grounded.
Subsequent use of the product could then
result in a serious electrical shock to the user.
Tektronix is conducting the voluntary
recall to prevent this possibility of injury to
its customers and is part of the company’s
overall commitment to providing reliable,
safe and high-quality products. This recall
applies to approximately 60,000 TDS210
and TDS220 units with serial numbers
below the following:
TDS210: serial numbers below B049400 or
CO 10880
TDS220: serial numbers below B041060 or
C011175.
Customers should stop using the recalled
oscilloscopes immediately and contact
Tektronix to receive instructions on how to
return the product for modification.
Customers should not assume the product is
properly grounded even if it appears to be
functioning properly.
Customers can receive instructions for
returning the product by contacting Tektronix
Australia at 1 800 023 342 ext. 193, at 800-
835-9433 ext. 2400 in the US or by visiting
the company’s web site at
www.tek.com/measurement.
Alcatel plant
sold to Bluegum
Alcatel Australia’s manufacturing plant in
Liverpool, NSW has been acquired by con¬
tract manufacturer Bluegum Technology, as
part of a $250 million three-year agreement
between the two companies for the outsourc¬
ing of Alcatel’s telephone, switches and net¬
work product manufacturing activities. The
acquisition is said to position Bluegum
among the top 30 private companies in
Australia, and in the top 15 contract elec¬
tronics manufacturers in the world.
Bluegum CEO Mr Paul Zuber said that
the agreement would enable Australia to
78
ELECTRONICS Australia, September 1998
further develop its manufacturing potential
at home. “The Australian electronics hard¬
ware manufacturing market is worth A$7-8
billion, yet less than 15% is being serviced
by contract manufacturers today”, com¬
mented Mr Zuber.
Under the agreement, existing Alcatel
operations and management will remain,
providing a seamless transfer of current
management and 400 employees to Bluegum
on September 1. Peter Miller, manufacturing
manager of the Alcatel Liverpool plant,
becomes Director of Manufacturing for the
new Bluegum Telecommunications.
The agreement with Alcatel is a continua¬
tion of Bluegum’s expansion into the
Australian electronics contract manufacturing
business, which began with its purchase of
IBM’s Wangaratta plant in November 1997.
Iomega unveils
new USB Zip drive
Iomega Corporation has announced a new,
external Zip drive for use with a Universal
Serial Bus (USB) interface. The company
demonstrated the new drive in conjunction
with Apple Computer’s new iMac model in
New York at the MacWorld exhibition in July.
The new translucent ice-blue USB Zip drive
will have the USB interface built into the
drive, saving space on the desktop and elimi¬
nating the need for a larger parallel port or
SCSI conversion cable. The USB Zip drive is
designed to provide users of USB-equipped
computers, with Mac OS 8.1 or Windows 98
operating systems, the easy connectivity of a
hot ‘plug and play’ solution.
“IDC believes that USB will become prevalent
in the market this year with an estimated 90%
of desktops shipped this year with the technol¬
ogy”, said Kevin Hause, PC analyst
with International Data
Corporation. “USB’s market appeal
is based on its plug and play func¬
tionality and ability to provide users
with a single, higher bandwidth port
for a range of peripherals.”
USB is a low cost, high-speed
peripheral expansion architec¬
ture that provides data transfer
rates up to 12Mb/s. USB inter¬
facing peripherals can be
plugged and unplugged from
the USB interface anytime,
without requiring the user to
restart their system to initiate or
re-initiate use. The USB spec
also supports up to 127 devices
on a single computer system.
The new USB Zip drive is expected to be
available late in 1998. The estimated US
street price is not expected to exceed
US$149. The drives will be designed to be
compatible with an installed base of tens of
millions of Mac and PC formatted Zip disks.
Sanyo licenses PM’s
HDCD technology
Sanyo Electric’s MOS-LSI division, one of
the world’s leading suppliers of integrated
circuits for consumer audio CD playback
systems, has licensed Pacific Microsonics’
high fidelity HDCD decoding and precision
filtering technology for Sanyo’s new general
market audio chip.
“Sanyo is very pleased to be working with
Pacific Microsonics because HDCD has
become a symbol of high quality digital
audio worldwide”, said Toshiyuki Ozawa,
Department Manager of Sanyo’s System
Development Division. “With Sanyo’s large
scale integration design skills and high vol¬
ume manufacturing capability, we will be
able to offer consumer electronics manufac¬
turers a high quality HDCD chip that meets
both their performance and aggressive cost
requirements.”
The new chip will be an enhanced ver¬
sion of Sanyo’s current industry leading
general market audio product, which inte¬
grates all major CD player circuitry on a
single chip. Sanyo will add the same high
fidelity HDCD decoding and HDCD filter¬
ing technology used in Pacific
Microsonics’ PMD-100 chip, a standard
component in high end CD players around
the world. Also, the D/A converters in the
new chip will be upgraded from 16 to 18
bits. Target consumer product applications
include high volume CD players, changers,
portables, mini-component systems and
automotive audio products. Sanyo expects
samples to be available in the second half
of 1999, and production quantities to be
available soon thereafter.
In January, Motorola announced that it is
adding HDCD to its 56362 DSP, and in
March, Analog Devices announced it is
adding HDCD to its SHARC DSP. Target
consumer product applications for these chips
include A/V receivers and DVD players.
Developed by Pacific Microsonics in
Berkeley, California, HDCD (High
Definition Compatible Digital) is a patent¬
ed process for delivering on Compact Disc
the full richness and detail of the original
microphone feed. HDCD encoded CDs
sound better because they are encoded with
20 bits of real musical information as com¬
pared to 16 bits for conventional CDs.
Philips shipping
CleverCast DVB cards
Philips Digital Video Systems Company, a
leader in the field of digital data broadcasting,
has begun mass production of the CleverCast
PC-DVB Receiver card. Volume shipments
Scientists and support
people working in
Antarctica can now
use cellular phones to
call anywhere in the
world, thanks to a new
cell site installed last
May by Lucent
Technologies
engineers. The site is
satellite-linked to
Rivadavia in
Argentina.
(Business Wire)
HDCD provides more dynamic
range, a focused 3-D sound stage
and extremely natural musical
timbre. HDCD recordings offer
improved sound quality on any
CD player, and when played on
HDCD equipped players, they
are claimed to provide the ulti¬
mate in sonic fidelity.
Pacific Microsonics says that
over 50 million HDCD CDs have
been shipped to date and over
100 HDCD equipped CD player
products are now available.
ELECTRONICS Australia, September 1998
79
were to begin in the second quarter of 1998.
Poised to gain a competitive advantage
by being the first to announce volume
shipments, Philips is prepared for the high
market demand of PC-DVB Receivers.
The Philips CleverCast PC solution is
claimed to be compatible with every IP
based application. Applications such as
Precept Software’s IP/TV, StarBurst,
Microsoft NetShow, Philips Broadcast
FTP and services from DataCast and The
Fantastic Corporation are said to run
seamlessly on the platform, with
CleverCast PC’s adherence to both broad¬
casting standards (DVB SI-Dat) and
Intemet/PC standards (TCP-IP, Microsoft
Windows 95/NT).
To date, Philips has successfully sup¬
plied complete end-to-end solutions, from
uplink equipment to PC-DVB Digital
Receivers and DVB compliant Data
Broadcasting Systems — to such presti¬
gious international broadcasters as
Deutsche Telekom (Germany), Teracom
(Sweden), Telenor (Norway), RAI (Italy)
and Digital Express (USA).
The CleverCast PC Data Broadcasting
System allows for the reception of digital
multimedia data (audio, video and data)
which is broadcast at high speeds through
digital satellite transmission systems to per¬
sonal computers. This application makes it
possible to transmit data in a digital form to
a single user (unicast), a group of users (mul¬
ticast), or to all users with access to the ser¬
vice (broadcast). The platform can be used
for new services such as Broadcast File
Transfer and High Speed Internet.
High-speed data broadcasting to the PC,
currently available at a rate of 16Mb/s, will
be available at an increased rate of 45Mb/s
before the end of 1998. Since the data, usu¬
ally in a compressed form, need only be
transmitted to the satellite network once, this
data ‘push’ method saves bandwidth and
reduces transmission costs drastically.
Intel introduces
Pentium II Xeon
Intel Corporation has introduced a new family
of processors designed to meet the demanding
requirements of mid-range and higher servers
and workstations. The new Pentium II ‘Xeon’
processors feature technical innovations
specifically designed for workstations and
servers which run demanding business appli¬
cations such as Internet services, corporate
data warehousing, digital content creation,
electronic and mechanical design automation.
The Pentium II Xeon processor delivers
industry leading performance from its larger
and faster Level 2 (L2) caches, multiprocess¬
ing capabilities and a 100MHz system bus.
Systems based on the Pentium II Xeon can be
configured to scale up to four or eight proces¬
sors and beyond. The combination of the pure
performance of the Pentium II Xeon proces¬
sor and this scalability are claimed to bring
exceptional levels of price performance to the
server and workstation market segments.
Intel claims Pentium II Xeon processor-
based servers deliver the industry’s best
four-processor TPC-C result to date, with a
rate of 18,127.40 tpmC running on
Compaq’s ProLiant 7000 6/400 with
Microsoft Windows NT4.0 and SQL
Server 7.0. (The benchmark measures the
rate of common database transactions in an
online transaction processing environment
such as a customer service call centre).
Key features of the Pentium II Xeon
processor include a 0.25 micron P6 microar¬
chitecture core featuring Dynamic
Execution, operating at 400MHz; 512KB and
1MB L2 cache options; Intel’s Dual
Independent Bus featuring a 400MHz L2
cache bus, operating at the same speed as the
processor core, a 100MHz transactional
System Bus and 100MHz SDRAM and EDO
memory support, allowing faster communi¬
cation between the processor and other parts
of the computer system; support for greater
than 4GB of memory for servers using Intel’s
Extended Server Memory Architecture; and
addressable memory support up to 64GB.
DKD accredits
Fluke calibrators
Fluke Corporation claims it has become the
first US electronics manufacturer to receive
accreditation for both its standards laboratory
and calibrator production facilities by
Germany’s Deutscher Kalibrierdienst (DKD),
the laboratory accreditation body of the
German national standards organization. The
accreditation allows Fluke to provide globally
recognized, legally traceable test data for
most Fluke calibrators, eliminating the time
and expense to re-calibrate instruments
shipped to users outside the United States.
According to Fluke standards laboratory
manager, Ray Kletke, this accreditation is
something of a landmark. “This is the first time
anyone in the US has worked with a member
of the European co-operation for Accreditation
(EA). It involved a lot of collaboration between
Fluke and the national standards organizations
u.
Ul
£
<0
£
• The postal address for computer-aided
design tools specialist Protel
International has changed; it’s now PO
Box 427, Frenchs Forest 1640.
• Frequency control product supplier Hy-Q
International (Australia) has changed its
email address, which is now sales@hy-
q.com.au.
• Software and computer peripherals dis¬
tributor Dataflow Computer Services
has appointed former Philips Australia
Chairman and CEO Justus Veeneklaas
to its board of directors.
• Technical training specialist TTC Australia
has introduced technology training
courses which can be supplied as either
cost effective computer-based packages
or professionally run courses. Courses
available during September 1998
include 2M Transmission Fundamentals,
Frame Relay Technology &
Implementation, ATM Technology &
Implementation, ISDN Fundamentals &
Implementation, and An Introduction to
LANs and Internetworking. For more
information contact TTC on (03) 9563
4800 or (02) 9926 1447.
• SMT China V8, the 2nd China
International Surface Mount Technology
Exhibition, will be held September 22-
25 at the INTEX International Exhibition
Centre in Shanghai. For more informa¬
tion contact organisers Messe &
Kongress GmbH in Stuttgart, Germany;
fax (+49 711) 66197-79. ❖
80
ELECTRONICS Australia, September 1998
of the US and Germany.”
The Fluke production facility is accredited as
an extension of the corporate standards labora¬
tory, so each final test system on the production
line falls under the lab’s responsibility. Each
system is highly automated, eliminating most
manual intervention in the final test stages.
Finally, all stations are monitored continuously
as part of a statistical process control loop.
AMD to deliver
chip for HomePNA
AMD, a founding member of the Home
Phoneline Networking Alliance (HomePNA),
has announced that it will deliver single chip,
low-cost silicon implementations based on the
Alliance’s initial IMb/s specification for tele¬
phone wire networking. Production samples
will be available for integration onto mother¬
boards, circuit boards, network interface cards
and other consumer electronics devices during
the Q4 of 1988.
The HomePNA is a consortium of the lead¬
ing computing and communications compa¬
nies, working together to ensure the adoption
of a single, unified phone line networking
standard. The HomePNA has adopted a robust
technology based on existing Ethernet stan¬
dards to support the use of telephone wiring to
network computers, peripherals and digital
devices throughout the home.
“AMD is committed to helping the
HomePNA drive industry standards for
phone line networks capable of meeting the
growing requirement within the home for
easily deployed networking capabilities,”
said Tom Eby, Group VP of AMD’s
Communications Group.
Founding members of the HomePNA
include 3Com, AMD, AT&T Wireless,
Compaq, Epigram, Hewlett-Packard, IBM,
Intel, Lucent, Rockwell and Tut Systems.
Further HomePNA information is available on
the World Wide Web at www.homepna.org.
P&G transducers
help launch Ariane 5
Four different types of linear displacement
transducers (LVDTs) made by control tech¬
nology specialists Penny & Giles have been
used in the European space program. The
LVDTs were used on the solid boosters, the
first stage Vulcain engine and the second stage
Aestus engine of the Ariane 5 launch vehicle.
LVDTs are installed on the direct drive
valves and servo actuators used for both the
thrust vector control of the solid boosters and
the Vulcain engine of the first stage; and the
Aestus engine of the second stage. The LVDTs
for the solid boosters and Vulcain engine were
supplied to SABCA (Societe Anonyme Beige
de Constructions Aeronautiques) of Belgium,
who were involved in the design and manufac¬
ture of direct drive valves and servo actuators
for the project.
Penny & Giles were introduced to SABCA
by their Belgian distributor EIG Benelux, and
were selected to supply LVDTs for the Ariane
5 servo actuators following an engineering
development programme to produce qualified
product to SABCA’s specifications. The com¬
pany received its first order for the project in
1989 and their LVDTs made it into space with
the successful launch of mission 502 from
Kourou, French Guyana on 30th October 1997.
A third Ariane 5 launch is scheduled for
Summer 1998 and commercial launches are
expected to begin in the second half of 1998.
More information is available on Penny &
Giles products from distributor Control
Devices, on (02) 9356 1943.
Growth expected
in flat panels
Although the North American market for
portable computers is the world’s largest,
most displays are incorporated into comput¬
ers overseas, mainly Taiwan. The fastest and
most profitable growth is expected to be in
applications other than portable computers.
Major manufacturers are now targeting
emerging markets such as flat panel display
(FPD) monitors and non-portable TVs.
According to strategic research conducted
by Frost & Sullivan (www.frost.com) and
presented in the report North American
Commercial and Consumer Electronics Flat
Panel Display Markets , the total market is
expected to reach almost US$9.5 billion in
2004. As prices become viable, the FPD
monitor market and non-portable FPD TV
market are expected to grow the fastest.
The improvement of established technolo¬
gies and the development of new ones are
major drivers in the FPD market. New tech¬
nologies including plasma, field emission dis¬
plays (FED) and digital micromirror devices
(DMD), as well as improvements in liquid
crystal displays, are expected to create new
markets and challenge existing technologies.
“The major concern for market partici¬
pants is achieving low price through cost
effective manufacturing”, says Frost &
Sullivan Analyst Jouni Forsman. Currently,
FPD prices are too high to allow for the max¬
imum attainable market penetration. ❖
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ELECTRONICS Australia, September 1998
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READER INFO N0.29 READER INFO N0.28 READER INFO N0.27
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ELT- DIC 9/98
VIDEO CAMERAS - SURVEILLANCE -
CCTV SPECIALS: 380 x 0.2 SILICON
PCB MODULE $69! 450 TVL DIGITAL
COLOUR PCB $320! DOME HOUSINGS
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from $88. Dome from $91. DIGITAL
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ACCESSORIES: 30 + Lenses, Infra-Red
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Quads 4 pix 1 screen from $280.
SWITCHERS 4 & 8 Ch from $126.
MULTIPLEXERS FULL-SCREEN FULL-
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Manual $95 or FREE! 2 Year WARRANTY
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Ask for our Illustrated Catalogue/Price List
with Application Notes. Allthings Sales &
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FREE PCB DESIGN SOFTWARE -
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Schematic. 100 to Unlimited pin versions
from $15 or download from ME:
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SPICE SIMULATION - Send $5 for
evaluation CD - demos, models &
info on Intusoft SPICE products.
ME Technologies PO Box 40,
Dyers Crossing NSW 2429,
Fax: 02 6450 2341
Rain Brain Sprinkler Kits:
Also 8 and 60 channel temp,
monitors with PC Data logging.
Mantis Micro Products, 38 Garnet
Street. Niddrie, 3042. (03) 9331 4786,
Fax (03)9331 4782
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PIC84 PROGRAMMER and PIC
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or (02) 9789 3616
Unusual Books: Electronic Devices,
Fireworks, Locksmithing, Radar
Invisability, Surveillance, Self-Protect¬
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complete catalogue, send 95 cents in
stamps to: VECTOR PRESS, Dept E,
PO Box 434 Brighton SA 5048.
Amidon Ferromagnetic Cores:
For all RF applications. Send business
size S.A.S.E. for data/price to RJ & US
Imports, Box 431, Kiama NSW 2533.
Agencies at Assoc TV Service, Hobart;
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AUDAX High-Tech European Speaker
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ME Technologies 02 6550 2254
PC Display Splitter Kit $79
EA Jan98 Also sold built up
QUESTRONIX (02) 9477 3596
Photosensitive copper clad for DIY
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hobbyist. Many other items and
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into plastic & aluminium cases. Full
list of services and goods at
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Ph: (02) 9743 9235.
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of plastic cases plus screen printing
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Ph: (02) 9743 9235,
Logic Analyser lOOMs/s 32-Channel
Kit $1275. Stand alone, not a plug in
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Ph: 02 9878 4715. Fx: 02 9888 7679.
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All manuals of the website:
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Revised, no prototype area, “8051
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Inductance
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Capacitance
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Resistance
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Computronics
Corporation Ltd
6 Sarich Way. Technology Park, Bentley, WA, 6102
Ph 08 9470 1177 Fax 08 9470 2844
Specifications at www.computronics.com.au
Early and vintage HiFi, amplifiers,
turntables, speakers, valves, pre 1969.
Cash paid (07) 5449 1601
OLD video recordings of TV Station
broadcasts from 1956 to 1980.
T.Ernslie, 13 Warren St, Ryde 2112.
Ph: (02) 9888 2062.
WW II Army Suitcase Transmitters,
Receivers, Type A. Mark III + Type 3.
Mark II, & MCR 1, RX. A.W.A. AMR
100 RX. No.11, 19, 22, Sets or Part
Sets, any condition. Pay reasonable
price, Ray VK4FH. PO Box 5263 Daisy
Hill, Brisbane. Ph: (07) 3299 3819.
Fax: (07) 3299 3821.
ELECTRONICS Australia, September 1998
83
Solid Stat<L,,„
Keeping you informed on the latest developments in semiconductor technology
Analog CCD and CIS
signal processor
Analog Devices has released the AD9816,
a 12-bit, 6MS/s Analog-Front-End (AFE)
that integrates an analog to digital convert¬
er (ADC) with the analog circuitry needed
for three-channel (RGB) image condition¬
ing and sampling. The AD9816 can be
programmed through a serial interface,
and also includes an input pin for offset
adjustment that will give users greater
flexibility to use any type of CIS sensor
currently on the market.
The AD9816 will perform all the signal
processing necessary for applications such
as mid- to high-end desktop scanners, dig¬
ital still cameras, medical X-rays, security
cameras and any instrumentation applica¬
tions that ‘read’ images from CCD and
CIS sensors.
The signal chain of the AD9816 consists
of an input clamp, correlated double sam¬
pler (CDS), offset adjust DAC, programma¬
ble-gain amplifier and a 12-bit CMOS ADC
core. It has been designed to run at 6MS/s
with good linearity and noise performance
and to guarantee no missing codes at maxi¬
mum conditions — while running at 6MHz
in three-channel CDS mode.
The AD9816 has a DNL of+/-0.33LSB.
At gain = lx noise is only 0.5 LSB RMS. In
fact, even at gain = 6x the noise is only 0.8,
which is far superior to the AD9816’s clos¬
est competitor. Crosstalk on the AD9816 is
less than 1 LSB.
The AD9816 operates from a 5V supply
and typically consumes just 500 mW of
power. For more information circle 271 on
the reader service card or contact Analog
Devices, PO Box 2098, Rosebud Plaza 3939.
Multimode Ultra2
SCSI terminator
A new multimode SCSI terminator that holds
termination resistance more closely to the
110-ohm spec than comparable devices is
available from Dallas Semiconductor. Fully
compliant with emerging Ultra2 SCSI speci¬
fications, the DS2118M is a multimode, low-
voltage differential/single-ended (LVD/SE)
Ultra2 SCSI terminator that provides active
termination for nine signal line pairs.
Because Dallas laser-trims resistor ladder
structures within each device, the DS2118M
can hold the SCSI-specified 110-ohm termi¬
nation resistance to +/-5%. Comparable
devices show a tolerance of +/-8%.
“As a multimode SCSI terminator, the
DS2118M contains circuitry that determines if
a bus requires SE or LVD termination,” said
Charles Tashbook, product manager. “The
chip automatically selects the proper mode.”
The DS2118M has a low power-down
capacitance of 3pF and on-chip thermal
shutdown circuitry.
For more information contact Dallas
Semiconductor, 4401 S. Beltwood Parkway,
Dallas Texas 75244-3292 USA.
‘Smallest 500mA
LDO regulators
Micrel Semiconductor has announced its
new 500mA range of low power, low
dropout (LDO) regulators, the M1C5219
and M1C5216. Both devices are available in
power MSOP-8 and Micrel’s TttyBitty’
SOT23-5 packaging, claimed to make them
the industry’s smallest 500mA regulators.
Micrel’s power MSOP-8 package has a
fused leadframe to improve thermal resis¬
tance, providing it with the power handling
capabilities similar to a much larger SO-8
package. Power dissipation constraints typi¬
cally limit output current in SOT23-5
devices to less than 150mA. The M1C5219
and MIC5216 provide 500mA capability for
applications with occasional or periodic
demand for high current; these applications
have previously required much larger prod¬
ucts in SO-8 packaging.
The M1C5216 and M1C5219 are suited
for mobile applications where small size and
high efficiency are critical. Low dropout
voltage of 300mV at 500mA, low quiescent
current of 80uA and a shutdown pin extend
battery life, while in shutdown, the devices
have a near-zero supply current. Tight initial
accuracy of 1% and excellent line and load
regulation ensure a precise output voltage.
Both the MIC5219BM5 and MIC5216BM5
are available with adjustable or fixed output
voltages of 3.0V, 3.3V, 3.6V or 5.0V.
For more information circle 272 on the
reader service card or contact GEC
Electronics Division, Unit 1, 38 South
Street, Rydalmere NSW 2116.
16-bit DAC with
serial micro interface
Burr-Brown’s new DAC716 is a high resolu¬
tion, monolithic 16-bit digital-to-analog con¬
verter (DAC) with serial microprocessor inter¬
face, specified for industrial process and con¬
trol applications such as robotics, motor speed
control, and equipment motion controllers.
The DAC716 is complete with an internal
+10V temperature compensated voltage refer¬
ence, current-to-voltage amplifier, a high¬
speed synchronous serial interface, a serial out¬
put which allows cascading multiple convert¬
ers, and an asynchronous-clear function which
immediately sets the output voltage to zero.
The output voltage range is 0 to +10V
while operating from +/-12V to +/-15V sup¬
plies, and the gain and bipolar offset adjust¬
ments are designed so that they can be set via
external potentiometers or external DACs.
The output amplifier is protected against
84
ELECTRONICS Australia, September 1998
short-circuiting to ground.
Other features include 600mW power
dissipation, fast settling time (lOus to
0.5LSB), and 15-bit monotonic perfor¬
mance over temperature.
For more information circle 273 on the
reader service card or contact Kenelec, 2
Apollo Court, Blackburn 3130.
Triple 140MS/S ADC
for SXGA LCD monitors
Analog Devices has introduced the AD9483,
a triple 8-bit analog-to-digital converter
(ADC) that has been optimized for digitizing
RGB graphics signals from personal com¬
puters and workstations, as needed to drive
LCD monitors.
With a 140MS/s encode rate and full-power
analog bandwidth of 300MHz, the AD9483
can support display resolutions up to 1280 x
1024 at 75Hz, with sufficient input bandwidth
to accurately acquire and digitize each pixel.
These features, along with a 1V peak-to-peak
analog input range and low power dissipation
(less than 1.5W at +5.0V) makes the AD9483
very suitable for RGB graphics processing for
LCD monitors, graphics projectors, and plas¬
ma display panels.
To minimize the user’s system cost and
power dissipation, the AD9483 includes an
internal +2.5V reference and track-and-hold
circuit. All the user has to do is provide +5V
and an encode clock — which means that no
external reference or additional drive circuit¬
ry will be needed for many applications.
The encode input of the AD9483 inter¬
faces directly to TTL, CMOS, or positive-
ECL logic, and will operate with single-
ended or differential inputs. The digital out¬
puts are three-state CMOS and may be pow¬
ered from either a +3.3V or +5V supply.
For more information circle 274 on the
reader service card or contact Analog
Devices, PO Box 2098, Rosebud Plaza 3939.
Dual channel 20-bit
delta-sigma ADC
Burr-Brown’s new DDC 112 is a dual input,
wide dynamic range, charge digitizing ana¬
log-to-digital converter (ADC) with 20-bit
resolution. It is designed to accept low-level
input currents from direct photosensor digi¬
tizer applications such as CT (computed
tomography) scanners, infrared heat detec¬
tors, liquid or gas chromatography, and
blood analysis.
The DDC 112 combines the functions of
current-to-voltage conversion, integration/
input programmable full scale gain amplifi¬
cation, A/D conversion, and digital filtering
to produce precision, wide dynamic range
digital results. Charge integration is contin¬
uous as each channel contains two integra¬
tors — while one is being digitized, the
other is integrating.
The device offers the ability to use
external integrating capacitors, thus allow¬
ing a user-programmable full-scale range
up to lOOOpC. In addition, the serial I/O
register can be configured to allow multi¬
ple DDC 112 units to be cascaded, mini¬
mizing interconnections. Other features
include single supply operation, integral
linearity (+/-0.005% reading +/-0.5ppm
FSR), and digital filter noise reduction
(3.2ppm RMS).
For more information circle 275 on the
reader service card or contact Kenelec, 2
Apollo Court, Blackburn 3130.
MCU support 1C
has 3000 gate CPLD
WSI’s latest addition to its family of flash
MCU support ICs, the PSD8XXF2 inte¬
grates high-density (serial or parallel pro¬
grammable) concurrent flash memory with
complex programmable logic, SRAM,
extra I/O and a programmable microcon¬
troller interface.
The PSD8XXF2 allows flash memory
erase/write operations to be performed dur¬
ing program execution by providing two
flash memory arrays of 128K and 32K bytes.
The 128KB flash array is used for system
program store and the 32KB (four 8KB sec¬
tors) array is used to store boot algorithms,
programming algorithms and NVM data.
Since the system can execute code from
either flash array, each can be programmed
concurrently with system operation.
In addition to the two ISP flash arrays,
the PSD8XXF2 has a 2KB scratchpad
SRAM, a 3000 gate Micro-Cell CPLD, a
special ISP decoding PLD, extra I/O and a
programmable interface to most microcon¬
trollers from Philips, Intel, Motorola,
Siemens and others. A JTAG interface is
provided for first-time and subsequent ser¬
ial ISP that is six times faster than parallel
programming.
For more information contact WSI, 47280
Kato Road, Fremont 94538 California, USA. ❖
LUNDAHL
-TRANSFORMERS-
Microphone, Line and Splitting
Video Isolation
Hybrid
Vacuum Tube Drive & Output
Control Devices
Phone: (02) 93561943
Fax: (02) 93561908
ELECTRONICS Australia, September 1998
85
READER INFO NO.30
Products
Claimed to be the smallest yet, the recently introduced GSC20
compact 20W switching power supply from Powerbox is very suit¬
able for overhead projectors, data communications devices and
any application needing a compact, portable and reliable power
source. It has a footprint no bigger than a business card, measuring
87.5 x 50 x 17.2mm, but delivers an output of 4W/in'.
With an input voltage range of 90 - 264V AC, the GSC20 has
fixed frequency operation and standard overvoltage protection,
and complies with EMI FCC Class B, CISPR22B. It is approved to
UL1950, IEC950, CSA 22.2 No.234 Level 3 and EN60950.
The GSC20 is available in five versions, with power levels from
5 to 28 volts and carries a two-year warranty. Medical configura¬
tions are available on request.
For more information circle 241 on the reader service card or con¬
tact Powerbox Australia, 4 Beaumont Road, Mt Kuring-gai 2080.
Handheld tester finds comms cable faults
The new Tektronix TV90 CableScout time domain reflectometer
(TDR) is a low-cost, high performance handheld instrument for
maintaining and installing communications cabling systems.
Outside plant technicians and installers in the cable television
(CATV) industry can use the instrument to locate and troubleshoot
cable faults in new or existing coaxial drop cable.
The TV90
CableScout’s
easy-to-use one-
step setup and
two-step test
ensures quick
results, reducing
repair time.
Technician train¬
ing time is also
decreased with the
help of a simple
user interface.
The instrument
can test cable dis¬
tances greater than
4000 feet and pro¬
vides distance accuracy to +/-2 feet. It is weather-proofed for
operating temperatures of 0 to +45°C with 95% humidity. It is
also easily portable, weighing only 1kg and measuring just 211 x
141 x 43mm.
For more information circle 242 on the reader service card or
contact Tektronix Australia, 80 Waterloo Road, North Ryde 2113.
PC-based power analyser
The EasyPower Measure is a first-of-its-kind, PC based power
measurement instrument that can be used as a user-interactive
three-phase power analyser or a stand-alone power-quality mon¬
itor. At a fraction of the price of other full featured analysers,
the portable system provides real-time waveform display and
data management using the familiar graphical user interface and
intelligence of a notebook PC, which eliminate the blind collec¬
tion and disorganised information storage associated with typi¬
cal power analysers.
With the EasyPower Measure system, the PC is the instru¬
ment. The measurement front-end supplies the voltage and cur¬
rent data directly to a notebook PC in real time via four voltage
inputs (1250V peak differential via sheathed banana safety con¬
nectors) and four current clamp inputs. As data is collected, the
PC performs all of the power calculations, provides graphics and
numeric tables, and stores the data to its hard drive in real time.
Data collection accuracy is +/-0.03% for both current and volt¬
age and measurement resolution is 12 bits. Sample frequency is
128 samples per cycle nominal and 256 points per cycle maxi¬
mum, while the maxi¬
mum single-channel
sample rate is 500kHz.
The EasyPower
Measurement platform
offers five power mea¬
surement modes. The
Phasor Diagram mode
comes standard with the
EasyPower Measure;
Detailed Harmonics,
Spectrum Analyser,
Cycle-by-Cycle and
Event/Demand Capture
measurement modes are
available options. With
all of these modes, wave
shapes, calculated waveforms and numeric tables can be easily
viewed on the PC’s monitor in real time.
For more information circle 246 on the reader service card or
contact Scientific Devices Australia, 118 Atkinson Street,
Oakleigh 3166.
86
ELECTRONICS Australia, September 1998
RF chokes for PCB mounting
The new Schaffner RN-series chokes are designed to provide high
attenuation of common mode interference in the range of 100kHz
to 3MHz, while differential mode signals in the operating range of
the chokes (DC - 1kHz) encounter zero inductance. Typical appli¬
cations include uninterruptible and switch-mode power supplies,
DC-DC converters, etc.
The RN series employ toroidal ferrite cores, offering a very high
inductance to volume ratio. Dual current-compensated windings
prevent core saturation when handling large peak currents.
The chokes are available for load current ratings from OJA to
10A with a voltage rating of 250V, and with path inductances
ranging from 0.7mH to lOOmH. They are well suited to PCB
mounting, being available in low-profile or small footprint
housings. The RN chokes are manufactured to rigorous quality
control standards, and withstand winding-to-winding and wind¬
ing-to-housing voltages of 1500V and 4000V AC respectively,
for one minute.
For more information circle 243 on the reader service card or
contact Westek Industrial Products, Unit 2, 6-10 Maria Street,
Laverton North 3026.
Hall effect AC/DC high current sensors
The L series range of Hall effect current sensors from Practical
Control Solutions are suitable for measuring currents from 500 -
2000 amps at frequencies from DC to 10kHz. The bipolar output
is +/-4V DC full scale, with a positive voltage for positive current
flow. A +/-15V 30mA DC power supply is required, which is also
available from PCS.
Unlike shunts the Hall effect sensors are fully isolated from the
DC bus, allowing the use of grounded control equipment. Also no
heat is dissipated across the Hall effect sensor, making the cooling
measures required for high current shunts unnecessary.
For more information circle 244 on the reader service card or
contact Practical Control Solutions, PO Box 1052, Mount
Waverley Delivery Centre, Mount Waverley 3149.
Handheld El tester
TTC Inc’s TTC 132B Communications Analyser is designed to
help field installation and maintenance by combining El (2Mb/s)
analysis features into a compact and rugged instrument. The
instrument’s Auto Configuration feature provides quicker and
easier instrument setup by determining and synchronising to the
framing format and pattern, thus automatically configuring to the
signal under test.
Easy to read Results Summary indicators provide instant
information to the user about circuit status. With this informa¬
tion available at the user fingertips, circuit problems are effi¬
ciently identified and sectionalised. For long term unattended
testing in the field, the TTC132B offers event-print and timed-
print outputs.
Additional highlights of the instrument include an active
timeslot display for simple identification of channel activity, as
well as results summary and front panel LED’s that offer imme¬
diate indication of critical circuit parameters such as error events,
alarm conditions, and configuration status.
The TTC132B is available immediately and will sell in Australia
and New Zealand for under A$7000.
For more information circle 245 on the reader service card or
contact TTC Australia, 41 Stamford Road, Oakleigh 3166. ❖
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• 3200 count
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has pF instead of A.
CIE128 Automotive DMM>
• 3200 count
• RPM,dwell, duty
cycle, pF, temp, freq
• Vdc, Vac, Q, 10A
• Auto off
< CIE 8088 Automotive DMM
• 3999 count
• RPM, pulse,dwell,
duty cycle, pF, temp, freq
• Vdc, Vac, Q, 20A
CIE 8042N Temperature DMM>
• 3200 count
• Temp-20 to 750°C,
• Vdc, Vac, Q, 20A
• Warning beeper
< CIE CA-60 Current Clamp Adapter
• Converts mA to mV, ac/dc
• Use 200mV/2V DMM ranges
• 60 A max, 9mm jaw
CIE 2608 AC/DC Current Clamp Meter >
• 57mm(0)/7Ox18mm jaw
• 1500Aac/2000Adc, 3999 count
• Vdc, Vac, Q, pF.freq
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All these meters are supplied with safety test leads, spare fuses (where
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READER INFO NO.31
AT&T buys TCI for US$48 billion
IN YET ANOTHER mega merger in the telecommunications industry, AT&T
announced it has agreed to pay a whopping US$48 billion for America’s largest
cable TV operator, Tele-Communications Inc (TCI). The deal opens the way for
AT&T to offer 33 million consumers and businesses a one-stop shopping option
for a broad range of services, from cable TV to home shopping to high-speed
Internet access and local and long distance telephone calls.
AT&T said it will set up a new company, to be known as AT&T Consumer
Services, which will offer one-stop shopping for long-distance and cellular phone
calls, cable television and high-speed Internet access. “We are merging with TCI
not just for what it is, but for what we can become together”, said AT&T chairman
Michael Armstrong. John Malone, chairman of TCI, has agreed to become a
member of the AT&T board.
Armstrong joined AT&T only last year. The TCI deal is the biggest in a series of
aggressive moves he has made in his short tenure. In late 1997, he bought
Teleport Communications Group for US$11.3 billion and recently AT&T said it
would lay off 18,000 people. He has also forged marketing alliances with several
Internet search companies.
TCI will now allow AT&T to provide local telephone service using TCI’s cable
TV network instead of using traditional phone lines. That gives AT&T a crucial,
direct link to consumer’s homes bypassing the Baby Bells’ infrastructure altogeth¬
er. “Today we’re beginning to answer a big part of the question about how we will
provide local service to US consumers”, Armstrong said.
Tl sells its
DRAM business
COMPLETING A YEAR-LONG move out
of the volatile memory chip market, Texas
Instruments has sold its memory chip busi¬
ness unit to the only other American DRAM
producer, Micron Technology for US$800
million. TI also said it will lay off 3500
workers due to continued weakness in the
overall semiconductor market. The lay-off,
about 8% of the company’s global work¬
force, will save the company US$270 mil¬
lion in annual operating expenses.
TI officials said the company is ridding
itself of the memory operations at a consid¬
erable loss. But prospects for a return to prof¬
itability appear so dim right now, TI believes
it stands to lose far more if it has to continue
making heavy R&D and capital investment
commitments to the memory field.
As part of the transaction, Micron will get
a number of state-of-the-art chip production
facilities in Italy, Singapore and Richardson,
Texas. TI will also close a second Richardson
operation with Micron getting the building.
The sale to Micron does not come unex¬
pected. For much of the past year, TI has
been reducing its committment to the memo¬
ry business, including selling or abandoning
memory business interests in joint ventures
with Taiwan’s Acer and Japan’s Hitachi.
Instead TI is focusing its semiconductor
business on digital signal processors and
other high-end circuits where there is consid¬
erably less competition or pressure on prices.
Is DVIX dead?
DVIX, A CONSUMER technology that
competes with standard DVD video, appears
on its last legs as sales of DVIX players and
disks have been lacklustre. Several major US
distribution retail chains are said to be close
to pulling out of the DVIX business and
focus on DVD instead.
DVIX allows consumers to purchase a
digital video disk for around US$5, com¬
pared to US$20 for regular DVD titles. But
users have to pay about US$3 for each
viewing. Consumers in the US have so far
shown a much stronger preference towards
owning DVD movies outright, or paying
about $3 to rent them from a local video and
DVD rental store.
Meanwhile, 20th Century Fox Studios
announced it is going to market DVD
movies, after holding out on the DVD busi¬
ness until now. The home video units of Walt
Disney and Time Warner have also
announced that they are banding together in
an international DVD distribution pact.
Under the deal, Warner Home Video will
distribute DVD movies from Buena Vista
Home Video, the Disney unit, in 30 territo¬
ries spread across Europe, the Middle East,
Africa and in former Soviet Union countries.
The agreement covers over 100 titles and
runs through the year 2000. Each of the
movies will be released simultaneously in
DVD and on videotape in the VHS format.
Rockwell quits
the chip business
ROCKWELL INTERNATIONAL, a leading
US producer of communications and other
ICs, said it is spinning off the chip business
into a separate company and laying off some
3800 workers in the process. The move is
expected to cost Rockwell US$625 million
in write-offs.
“The dynamics of semiconductor systems
are very different from Rockwell’s other
businesses, including its markets, products,
and investment requirements”, said
Rockwell chairman Don Davis in explaining
the decision. “Splitting the companies will
help Rockwell enhance their ability to
achieve their full potential”, he added.
The elimination of the IC operations fol¬
lows a 1996 decision to sell the firm’s
defense and aerospace operations. And a
year ago, Rockwell also spun off its automo¬
tive parts operations.
The IC spinoff is expected to be complet¬
ed by the end of the year. The company’s full
restructuring program will be completed by
the end of 1999.
LSI buys Symbios
as Adaptec bows out
SYMBIOS HAS YET another parent compa¬
ny, as LSI Logic announced plans to pay
US$769 million to Hyundai Electronics.
Earlier this year Adaptec, located just one
block down the street from LSI Logic in
Milpitas, had agreed to pay US$775 million
agreement for Symbios. Adaptec said it did¬
n’t expect the US Federal Trade Commission
to approve the merger and was ending the
merger process.
LSI officials said their company had been
one of several companies that bid on
Symbios. Hyundai initially chose Adaptec.
The FTC, however, objected, stating the
Adaptec/Symbios merger would concentrate
too much of the data communications inter¬
face market with one vendor.
The Symbios acquisition means LSI will
be able to offer its customers SCSI technolo-
88
ELECTRONICS Australia, September 1998
gy. “This major acquisition reflects our strat¬
egy of further penetrating the high-end com¬
puting and storage markets”, said Wilf
Corrigan, LSI Logic chairman and chief
executive. “This is the largest acquisition in
the history of LSI Logic. LSI goes from
being a US$1.3 billion company to being a
$2 billion company.”
Symbios is based in Fort Collins,
Colorado. The company makes client/server
ICs, host adapter boards and similar compo¬
nents. The company had 1997 revenues of
US$620 million and operating income of
$70 million before non-recurring charges.
AT&T, which acquired Symbios in the
NCR merger, sold Symbios to Hyundai in
1995. At that time, Adaptec was among the
bidders for the unit.
Motorola loses $1.3Bn
MOTOROLA’S TINY US$6 million operat¬
ing profit was overshadowed by $1.9 billion
in corporate restructuring charges that
caused the firm to report a net loss of US$1.3
billion. A year ago, it earned $392 million.
The impact of the Asian crisis, which is to
blame for most of Motorola’s woes is likely
to continue for at least another year, said
CEO Christopher Galvin.
Compaq begins
its restructuring
MAJOR LAY-OFF announcements are start¬
ing to come out of Compaq on a weekly
basis, in the wake of the Digital Equipment
merger and increasing softness in the person¬
al computer market. Compaq said it is firing
5000 additional workers and closing eight
facilities around the world as part of the
assimilation of Digital. The 5000 are part of
the total of 17,000 jobs, which are expected
to be lost as a result of the merger, a com¬
bined workforce reduction of 20%. The com¬
bined company will have about 67,000 work¬
ers when the consolidations are completed, a
process that will cost Compaq some US$5.4
billion in charges against its earnings.
The company is expected to save several
billion dollars year in operating expenses as
a result of the restructuring. “Integrating all
Compaq manufacturing operations into a
single, cohesive organization is essential as
we build the future Compaq”, said Compaq
CEO Eckhardt Pfeiffer. “It is important to
say that the loss we expect is different than
the operational result. This charge is posi¬
tioning the company for the future.”
Pfeiffer insisted that customers will bene¬
fit from the streamlining, which is aimed at
allowing Compaq to deliver 95% of its prod¬
ucts anywhere in the world in less than five
days. Currently it can take weeks, because
the company ships through distributors and
others who add to the time it takes to get the
product to the end user.
Gates alone at the
top with US$51 B
Not surprisingly, Bill Gates once again
topped Fortes Magazine's list of the world’s
richest and actively working individuals. The
magazine put Gates’ net worth at US$51 bil¬
lion, up 40% from a year ago.
Gates came within one bad day on Wall
Street of losing the title he has held for four
years, to the heirs of the late Sam Walton,
founder of the Wal-Mart chain of discount
superstores. They’re worth US$48 billion. ♦>
Will Apple bounce back with the iMac?
APPLE’S NEW IMAC computer took centre stage at the
recent MacWorld Expo in New York, and is expected to help
Apple report high sales and earnings in the next quarter.
Analysts expected Apple to ship as many as 400,000 iMacs
in the quarter ending in September.
A reviving Apple is also expected to report its third con¬
secutive quarterly profit for the period that ended June 30,
driven by strong demand for G3 systems, said CEO Steve
Jobs during an unscheduled keynote address at the
MacWorld show. “I am very pleased to tell you that it will be
our third consecutive profitable quarter”, said Jobs, who was
greeted with a thunderous standing ovation. Jobs said Apple
is putting new efforts behind supporting its customer base in
traditional Macintosh strongholds, such as desktop publish¬
ing, education and design.
A year ago Jobs and Microsoft chief Bill Gates were
booed at the then Boston-based MacWorld, when the two
announced Microsoft’s US$150 million investment in Apple
in return for stock and Internet Explorer becoming the
default browser on the Mac platform. Jobs said the program
has done wonders for Apple and the firm is working hard to
further strengthen its ties with Microsoft. “Despite the booes
of a year ago, this partnership has blossomed”, Jobs said.
“With this product we expect to see some additional
growth within the next six months at Apple”, Jobs said, not¬
ing that the iMac was Apple’s first product in several years
designed to appeal to both the educational and consumer
markets. The iMac, priced at US$1299 and loaded with
dozens of nicely designed features, is expected to revive the
magic of the early Macintosh line among consumers. The
iMac relies on a Motorola PowerPC processing chip that can
handle many computer tasks at far faster speeds than the
most powerful Wintel-based PCs.
“The iMac will deliver the best and easiest-to-use Internet
experience, tons of great consumer software, a variety of
great add-on peripherals, and yes, a high-speed 56K
modem. We will have lots of iMacs on dealer shelves for the
US launch on August 15, right on schedule,” Jobs said.
ELECTRONICS Australia, September 1998
89
Designer’s Guide
to Charging Li-Ion Batteries - 2
In the first of these articles we looked at the construction and operation of
modern lithium-ion cells and batteries, and their basic charging requirements.
Now we can look at the different kinds of charger circuit that can be used, and
the devices available to implement them.
by Joe Buxton Battery Chargers Design Engineer, Analog Devices Inc.
O nce the battery type has been chosen,
the next major question is which charg¬
er topology to use. This question needs
to be answered regardless of the battery cho¬
sen, but the following discussion concen¬
trates on Li-Ion.
The topology choice depends upon the
application and various system considera¬
tions. For example, an in-phone charger
(placed inside a cellular phone) would prob¬
ably need to be a switching regulator buck
topology, for the efficiency. A linear charger
in the same application would dissipate too
much power and generate too much heat.
Thus, the efficiency of the charger may be
more important because of the heat generat¬
ed rather than the power lost.
In all chargers, there must be a power
source. Typically it is an AC/DC adapter, often
called a ‘wall adapter’, ‘plug pack’ or ‘brick’.
An exception to this is a charger for use in a
car. This charger uses the car’s 12V DC.
For portable computers, the most common
approach is having an external brick that
provides a DC input to the computer and an
internal charger circuit. However the brick
can be moved inside the computer and com¬
bined with the charger. There are advantages
to each approach.
The external brick is typically an off-the-
shelf item that does not require a separate
design. The internal brick saves the con¬
sumer from having to carry additional cords
and the brick itself. Furthermore, combining
the brick with the charger can save system
cost. Essentially, the combination becomes
an AC/DC supply with 51% output voltage
regulation and programmable output current.
In the case of the external brick with an
internal charger, the ADP3801/02 buck
topology is ideal. On the other hand, the
ADP3810 charger was designed primarily
for AC/DC charger applications.
Another application is a cellular phone
charger. Again, there are several different
topologies: an in-phone charger, a desktop
charger and a car adapter charger. In the case
Fig.6: A ‘buck regulator’ type of dual Li-Ion
with an external P-channel MOSFET.
of the desktop charger, again the application
can be divided into an external brick (wall
adapter) or an internal brick/charger combi¬
nation. Also, since the charger sits on a desk¬
top, a linear charger such as the ADP3820
may be the best solution. However, an in¬
phone charger would probably require the
efficiency of a buck solution such as the
ADP3801/02.
Two key points will determine what type
of charger to use. First, is the efficiency (due
to heat generation) important for the applica¬
tion? If so, a switching-regulator-based
charger is the best choice. If not, then a
lower cost linear charger would be better.
Second, what will the system topology or
partition be? If there is a separate AC/DC
brick, then a DC/DC charger (either linear or
switching) is appropriate. However, the sys¬
tem cost may be lower if the brick function
is combined with the charger function. In
this case an off-line charger application is
battery charger , pairing the ADP3801 device
the best. All three of these circuit approach¬
es are detailed in the following sections.
A buck charger
The ADP3801 and ADP3802 are complete
buck type switching regulator battery charg¬
ers/controllers. Fig.6 shows an application
for a dual Li-Ion battery charger, pairing the
ADP3801 with an external p-channel MOS¬
FET. The ‘BAT PRG MUX’ allows one of
six final battery voltages to be selected.
These include one, two or three Li-Ion cells
(4.2V, 8.4V and 12.6V) and three intermedi¬
ate voltages for NiCad or NiMH cells (4.5V,
9.0V and 13.5V). Also, an input MUX
allows the part to sequentially charge two
independent battery packs, which could
require different voltages.
When a discharged battery is first placed
in the charger, the battery voltage is well
below the final charge voltage, so the current
sense amplifier controls the charge loop in
90
ELECTRONICS Australia, September 1998
constant current mode. The charge current
creates a voltage drop across the sense resis¬
tor RCS. This voltage drop is buffered and
amplified by amplifier GM1. Amplifier
GM2 compares the output of GM1 to an
external voltage at ISET and servos the
charger loop to make these voltages equal.
Thus, the charge current is programmed
using the ISET input. The output of GM2
controls the PWM duty cycle and the control
loop. When the charge current is too high,
the output of GM2 pulls the COMP node
lower. It reduces the duty cycle of the PWM,
decreases the charge current and provides
negative feedback to complete the charge
current control loop.
The output of GM2 is analog ‘ORed’ with
the output of GM3, the voltage loop amplifi¬
er. As the battery voltage approaches its final
voltage, GM3 comes into balance. As this
occurs, the charge current decreases, unbal¬
ancing GM2, while control of the feedback
loop naturally changes to GM3.
To guarantee 50.75% accuracy, a low drift
internal reference and high accuracy thin
film resistors are used. Including these com¬
ponents on-chip saves the significant cost
and design effort of adding them externally.
After the battery has reached its final volt¬
age, the current tapers off, as shown in
Fig.4(a). An internal comparator monitors
the charge current and — when it drops
below 80mA — the EOC (end-of-charge)
output pulls low. This signal can be used by
the system to show that the battery has com¬
pleted charging.
The LDO section of the chip provides a
51% regulated output voltage for use
either as a reference or as a supply
voltage for external circuitry such as a
microcontroller. The RESET pin gives
a power-on reset signal if needed by a
microcontroller.
Finally, pulling the SD pin low
places the ADP3801 in low current
shutdown with only the LDO in oper¬
ation. This can be very helpful in such
cases as momentarily stopping charge
(while a phone call is coming into a
cellular phone) to prevent switching
noise from interfering with the RF sig¬
nal and to reduce the supply current
when the charger is not needed. For more
information on the ADP3801/02, consult the
data sheet.
An off-line charger
The ADP3810 and ADP3811 are ideal for
use in isolated chargers. Because the output
stage can directly drive an opto-coupler,
feedback of the control signal across an iso¬
lation barrier is a simple task. Fig.7 shows a
simplified flyback battery charger.
The primary side control IC is a standard
current-mode flyback PWM controller. Its
wide duty cycle range makes it a good
RECTIFIER
AND FILTER
*CS Vcc 'SENSE
0UT ADP3810-8.4
COMP GNO
CHARGE
CURRENT
1 VOLTAGE
CONTROL
•WARNING LETHAL VOLTAGES
PRESENT. USE EXTREME CAUTION!
100W1
Rum
Fig.7: The simplified schematic for an off-line Li-Ion battery charger of the ‘flyback’
type, using an ADP3810 and a PWM3845.
choice for universal 70-270V AC operation
and for the additional requirement of 0% to
100% output current control. This charger
achieves these ranges while maintaining sta¬
ble feedback loops. The PWM frequency is
set to around 100kHz as a reasonable com¬
promise between inductive and capacitive
component sizes, switching losses and cost.
The primary PWM-IC circuit derives its
starting VCC through a 100 kO resistor direct¬
ly from the rectified AC input. After start-up a
conventional bootstrapped sourcing circuit
from an auxiliary flyback winding would not
work. The flyback voltage would be reduced
Figure 9. Linear Battery Charger
Fig.8: A linear Li-Ion battery charger
using the ADP3820 controller IC driving
an external P-channel MOSFET.
below the minimum VCC level specified for
the 3845 under a shorted or discharged battery
condition. Therefore, a voltage doubler circuit
provides the minimum required VCC for the
IC across the specified AC voltage range, even
with a shorted battery.
While the signai from the ADP3810/3811
controls the average charge current, the pri¬
mary side should have a cycle-by-cycle limit
of the switching current. This current limit
has to be designed such that — with a failed
or malfunctioning secondary circuit or opto-
coupler or during start-up — the primary
power circuit components (the FET and
transformer) won’t be over-stressed. As the
secondary side VCC rises above 2.7V during
start-up, the ADP3810/3811 takes over and
controls the average current. The primary
side current limit is set by the 1.612 current
sense resistor RLIM connected between the
power NMOS transistor and ground.
The current drive of the ADP3810/381 l’s
output stage directly connects to the photodi¬
ode of an opto-coupler, with no additional
circuitry. With 5mA of output current,
the output stage can drive a variety of
opto-couplers. An MOC8103 is
shown as an example. The current of
the photo transistor flows through the
3.3kO feedback resistor RFB, setting
the voltage at the 3845’s COMP pin
and thus controlling the PWM duty
cycle.
To minimize cost, a current-mode
flyback converter topology is
employed. Only a single diode is need¬
ed for rectification (MURD320) and
no filter inductor is required. A lmF
(lOOOuF) capacitor filters the trans¬
former current, providing an average DC cur¬
rent to charge the battery. Resistor RCS sens¬
es the average current, which is programmed
by a DC voltage on the VCS input pin. In this
case, the charging current has high ripple due
to the flyback architecture, so a lowpass filter
on the current sense signal is needed. This fil¬
ter has an extra inverted zero to improve the
phase margin of the loop. The lmF capacitor
is connected between VOUT and the 0.250
sense resistor.
To provide additional decoupling to
ground, a 220uF capacitor is also connected
to VOUT. Output ripple voltage is not criti-
ELECTRONICS Australia, September 1998
91
Charging Li-Ion Batteries
cal, so the output capacitor was selected for
lowest cost instead of lowest ripple. Most of
the ripple current is shunted by the parallel
battery, if connected.
The VCC source for the ADP3810/3811
can come from a direct connection to the
battery as long as the battery voltage
remains below the specified 16V operating
range. If the battery voltage is less than
2.7V (e.g., with a shorted battery or a bat¬
tery discharged below its minimum volt¬
age), the ADP3810/3811 will be in Under-
Voltage Lock Out (UVLO) mode and will
not drive the opto-coupler. In this condition
the primary PWM circuit will run at its
designed current limit.
The VCC of the ADP3810/3811 can be
boosted using the circuit shown. The
ADP3810’s VSENSE pin is connected direct¬
ly to the battery. This allows direct sensing
of the battery voltage for the highest accura¬
cy. The internal precision trimmed resistor
divider, the internal low drift reference and
the internal low offset amplifier all combine
to provide the 51% guaranteed specification.
A linear charger
Fig.8 shows the ADP3820 linear Li-Ion bat¬
tery charger controller. Its output directly
drives the gate of an external P-channel
MOSFET. As this circuit shows, a linear
implementation of a battery charger is the
simplest approach. In addition to the IC and
the MOSFET, only an external sense resistor
and input and output capacitors are required.
The charge current is set by choosing the
appropriate value of sense resistor, RS. As with
the ADP380x and the ADP3810, the ADP3820
includes all the components needed to guaran¬
tee a system-level specification of 51% final
battery voltage. The ADP3820 has an internal
precision reference, low offset amplifier and
trimmed thin film resistor divider.
A universal charger
Many applications only require the charger
to charge one specific battery. The form fac¬
tor (physical dimensions) of the battery pack
is usually unique, to prevent the plugging in
of other battery types. However, some appli¬
cations require the charger to handle multi¬
ple battery types and chemistries. The design
for these universal chargers is fairly compli¬
cated because the charger must first identify
the type of battery, program the charge cur¬
rent and voltage and choose the proper
charge termination scheme. Clearly, such a
charger requires some sort of microcon¬
troller intelligence.
Fig.9 shows a simplified block diagram for
a universal charger, using a microcontroller
with the ADP3801. The microcontroller is
used to monitor the battery voltage and tem¬
Fig.9: Simplified block diagram of a universal charger using the ADP3801 and a
microcontroller.
perature via its internal 8-bit ADC and multi¬
plexer input. It also keeps track of the overall
charge time. It may also monitor the ambient
temperature via a thermistor or analog temp
sensor. The ADP3801’s LDO (low-dropout
regulator) makes an ideal supply for the
microcontroller, and the RESET pin gener¬
ates the necessary power-on reset signal. The
LDO can also be used as a 51% reference.
When a battery is inserted into the charg¬
er, the first step is to identify the type of bat¬
tery placed in the charger. The most com¬
mon method of doing this is reading the
value of the in-pack thermistor. Different
values of thermistors are used to identify if
the battery is Li-Ion or if it is NiCad/NiMH.
This thermistor is also used to monitor the
temperature of the battery. A resistor from
the ADP3801’s LDO to the battery’s ther¬
mistor terminal forms a resistor divider and
generates a voltage across the thermistor for
the microcontroller to read. During this time,
the ADP3801 should be in shutdown, which
the uC controls via the SD pin.
When the battery has been identified, the
microcontroller can do a prequalification
of the battery to make sure its voltage and
temperature are within the charging range.
Assuming that the battery passes, the SD
pin is taken high and the charging process
begins. To program the charge voltage and
charge current, two digital outputs from the
uC can be used in PWM mode with an RC
filter on the BAT PRG and ISET pins. A
connection should also be made between
the EOC pin of the ADP3801 and a digital
input on the uC.
If the battery has been identified as
NiCad/NiMH, the uC must monitor the volt¬
age and temperature to look for -AV/At or
AT/At criteria for charging. After this point
has been reached, the charge current can be
set to trickle charge. A timer function is
needed to terminate charge if the charge time
exceeds an upper limit. This is usually a sign
that the battery is damaged and the normal
termination methods will not work.
The ADP3801’s final battery voltage
should be programmed to a higher voltage
than the maximum expected charging volt¬
age. Doing so prevents interference with the
NiCad/NiMH charging, yet still provides a
limited output voltage in case the battery is
removed. Meanwhile, the ADP3801 main¬
tains a tightly regulated charge current.
If the battery has been identified as a Li-Ion
battery, the ADP3801 is used to terminate
charge. The uC should monitor the EOC pin
for the charge completion signal. In some
cases, the charge is continued for 30 to 60
minutes after EOC to top off the battery. If this
is desired — upon receiving the EOC — the
timer function should be started. After the
allotted time, the ADP3801 should be placed
in shutdown to prevent constant trickle charg¬
ing. By using the high accuracy final battery
voltage limit of the ADP3801, the circuit can
guarantee safe Li-Ion charging without requir¬
ing an expensive reference and amplifier.
Conclusion
Li-Ion batteries offer exceptional advantages
in run time, size and weight. These advan¬
tages are leading to the widespread use of Li-
Ion in applications formerly served by
NiCad and NiMH batteries. Trends show the
Li-Ion is already the main battery choice for
portable computers, and the same will be
true for cellular phones in the near future. As
production of Li-Ion increases and their
costs reduce further, additional applications
will switch to this battery type.
Li-Ion charging does require high preci¬
sion circuitry to guarantee safe and complete
charging. Analog Devices offers a family of
parts that satisfy the demands of Li-Ion
while offering easy-to-use, cost-effective
circuitry. These parts cover a variety of
charger topologies, making the job of
designing a Li-Ion battery charger easy. ❖
92
ELECTRONICS Australia, September 1998
SPOTLIGHT
ON
SOFTWARE
i
m u*i]
Macro Virus Buster
by Jean-Baptiste Cattley
U nlike conventional viruses, which
infect programs, macro viruses
infect documents, such as Microsoft
Word .DOC files. These tend to spread
far more easily, because people tend to
exchange documents far more readily
than they exchange programs or disks.
Another thing going for macro viruses
is that they are platform-independent; an
infected document can harm a PC just as
easily as it can a Mac. This is because all
macro viruses (including the infamous
Concept, DMV and FormatC) work along
the same principles: auto-execute macros
are inserted into the document, which use
the built-in scripting language of the doc¬
ument’s parent application to copy them¬
selves into the application’s default tem¬
plate. (i.e. Normal.dot for Word docu¬
ments.) From there, they can infect all fur¬
ther documents edited.
As well as merely copying themselves, these
nefarious little macros can do some very
unpleasant things, such as deleting files or
inserting rude messages into all your print jobs.
Susceptible applications include Microsoft
Word, version 6 and above, and virtually all of
the Microsoft Office packages. Theoretically
any application with a powerful scripting lan¬
guage could be affected, but so far, macro
viruses seem to be limited to Microsoft Office
products, probably due to their popularity.
Virus buster
Although there’s a lot of anti-virus software
out there, you’ll have a hard time finding any
that provide decent protection against macro
viruses. This is where Leprechaun
Software’s Macro VirusBUSTER comes in.
MVB is designed only to detect and clean
macro virus infection in Microsoft Word
documents, so you wouldn’t want to give up
your conventional virus checker right away.
Unfortunately, Leprechaun software reports
compatibility problems with conventional
antivirus software, so you may have to decide
which kind of virus you fear the most. I found
no problems running MVB in conjunction
with VET Anti Virus, for example, but other
software may not be quite so forgiving.
As well as giving you the option to manu-
Computer viruses have gained
much attention in the past, and a
healthy proportion of people now
regularly run virus checkers on
any new software they obtain. A
fairly new addition to the viral
'gene pool’ is the macro virus,
which can wreak just as much
havoc as an ordinary file or boot
sector virus, but very few people
bother to check for them. Here’s
where Leprechaun’s new product
comes in...
ally scan directories for infected files, MVB
installs a VxD into the operating system that
checks all documents as they are accessed,
guaranteeing that all documents are scanned
before they can do any harm.
Installation
The software is supplied on two floppies,
one for use on Windows 3.lx systems, and
the other for Win95. There’s also a Windows
NT version available, but this wasn’t sup¬
plied in the package I received.
I installed the Windows 95 version, which
used InstallShield to set everything up, and
as a result I was later able to uninstall it
cleanly using the ‘Add/remove programs’
option in the control panel. Once installed, a
blue ‘M’ icon in the system tray indicates
that MVB is running, and that all office doc¬
uments will be checked as they are opened.
Every time you open, close or save a Word
document, MVB flashes a green tick mark in
the top right hand comer of your screen, to
indicate that it has checked the document and
found no macro viruses. This is a little dis¬
concerting at first, as it writes directly to the
screen instead of using a conventional win¬
dow or dialog box, but you soon get used to it.
Manual scanning is quite straightforward
— a button on the MVB main window brings
up a directory requester, allowing you to
select a directory to scan. Interestingly, if
you want to scan a single file, you have to
find it in Explorer and drag it on manual¬
ly; surely a standard file requester instead
of a directory requester would have been
more appropriate? Once manual scanning
has finished, MVB proclaims in a broad
Australian accent “The scan was complet¬
ed with no problem”. This is fun at first,
but after the fifth repetition, it wears some¬
what... Luckily, there is a way to turn it off
in the setup panel.
Perhaps the most interesting aspect of
Macro VirusBUSTER is that along with
normal vims signature scanning, (as used
by conventional vims checkers) it uses a
process called Heuristic Scanning. In this
mode, MVB looks at the actual code con¬
tained within any Word macros, and tries
to determine whether that code could do
anything harmful; in this way, it can theoret¬
ically detect previously unknown macro
viruses. For this reason, Leprechaun
Software have splashed ‘No upgrades need¬
ed!’ across the box, but I’m sure that a new
version of Office will fix that soon enough...
In actual use, Macro VimsBUSTER is trans¬
parent, fast and inconspicuous. I’ve had it run¬
ning for the best part of a month, and haven’t
come across any problems. The only real gripe
I have is the potential compatibility problems
with conventional vims checkers; a little more
information in the manual on this point would
have been useful, but I certainly haven’t struck
any problems — and the knowledge that the
next piece of email I receive won’t eat my hard
drive is certainly reassuring. ♦>
Macro VirusBUSTER
Macro Virus protection for Microsoft Word
documents.
: Fast, transparent operation,
minimal setup.
: Possible problems with other
anti-virus software.
:Leprechaun Software Australia,
PO Box 826, Capalaba QLD 4157. Phone
(07) 3823 1300; fax (07) 3823 1233, email
info@leprechaun.com.au; website at
http://www.leprechaun.com.au.
ELECTRONICS Australia, September 1998
93
Computer
News & New Products
USB-based instruments
National Instruments claims to be the first to
introduce instruments that connect to
Windows 95 PCs via the Universal Serial
Bus (USB). The family of instruments
includes a two channel, deep memory digital
oscilloscope (NI 5102); a 5-1/2 digit multi¬
meter (NI4060) and a high-precision temper¬
ature and voltage measurement instrument
(NI 4350). The instruments are compatible
with industry-standard software packages
including LabVIEW, LabWindows/CVI,
Visual C/C++, and Visual Basic.
CD Writer drive from Kodak
Kodak’s new Digital Science 2801 IDE CD
Writer allows PC users to take advantage of
the low cost and high capacity that CD-R
media provides, along with the very latest in
CD-R recording software technology.
The 2801 IDE CD Writer has several new
features over its predecessor, the 26001DE.
The 2801 IDE is an 8X read unit, has
improved software functionality, help fea¬
tures, user interface and audio writing capa¬
bilities. The new Writer also has an
improved installation manual to ensure a
trouble-free installation process.
The 2801 IDE CD Writer is an internal
ATAPI-IDE unit that is 2X speed write and
8X speed read. It is aimed at both mainstream
and high-performance personal computer
users and is ideal for desktop/web publish¬
ing, software developers, small office/home
office, business professionals and home
users. It simply plugs into the IDE port avail¬
able inside most IBM compatible PCs.
The software provided is CeQuadraf s lat¬
est offering, CeQuadrat ToGo! 4.5 along
with CeQuadrat Packet CD. The Packet CD
software allows users who want to share and
store their information to treat their CD-R
All of the USB-based instruments are
compatible with Windows 95 (OSR 2.1) and
Windows 98. Each instrument includes
instrument drivers and the appropriate acces¬
sories, cables, and probes.
The NI 5102 digital oscilloscope’s features
include 20MS/s real-time maximum sample
rate; lGS/s random interleaved sampling
(RIS); 15MHz input bandwidth; 663,000
sample record length; two input channels,
one analog trigger; 50mV - 5000V input
capability; and 8-bit vertical resolution.
The NI 4060 digital multimeter’s features
include 5-1/2 digit DMM with AC/DC cou¬
pling; true-RMS AC measurements, 20Hz -
25kHz; DC and AC input ranges of 20mV -
250V; and resistance measurements of
200C2 to 20M£1
For more information circle 161 on the
reader service card or contact National
Instruments Australia, PO Box 466,
Ringwood 3134.
Fast Ethernet link tester
The LanMaster Model 20 Link Tester pro¬
vides LAN installers and technicians a tool
to quickly test active Links in Fast Ethernet
disc just like any floppy disk or hard disk
drive by using the ‘File Save’ feature of
their existing software, or simply dragging
and dropping their files.
The 2801 IDE CD Writer measures 147 x
211 x 41 mm and has the same form factor as
a half-height 5-1/4” floppy drive. It’s avail¬
able for around $617 through a wide net¬
work — including retailers, camera dealers,
catalogues and traditional computer dealers.
For more information circle 160 on the
reader service card or contact Kodak Digital
& Applied Imaging, 173 Elizabeth Street,
Coburg 3058.
(lOObaseTX) and Standard Ethernet
(lObaseT) networks. In just three seconds,
the LanMaster 20 verifies Link operation,
identifies Fast Ethernet capabilities of
installed equipment and displays reported
fault status. The Model 20 also retails for
only $395, which is claimed to make it the
most affordable Fast Ethernet test instrument
available on the market.
The Fast Ethernet (IEEE 802.3u) standard
defines several new operating modes and
technical capabilities for LAN products.
Auto-sensing, Auto-negotiation and Full
Duplex operation are some of the new fea¬
tures that dramatically increase network per¬
formance and maintainability. These
enhanced modes and capabilities are only
optional requirements to the IEEE 802.3u
standard and installed equipment can have
very different levels of Fast Ethernet sup¬
port. These features can also be configured
during installation or operation further
increasing the difficulty of maintaining or
upgrading a network. The LanMaster 20
Link Tester provides important configura¬
tion and fault information by detecting and
decoding Link signals transmitted by the far-
end equipment. The decoded configuration
and fault information is displayed to the user
through eight backlit display cells.
The LanMaster 20 reduces Move, Add
and Change (MAC) problems by quickly
verifying connectivity and wiring polarity
for a new or modified network Link. It sim-
94
ELECTRONICS Australia, Setember 1998
READER INFO NO. 32
plifies troubleshooting by confirming physi¬
cal layer operation for an active Link and
improves network management by providing
equipment configuration information needed
to optimize system performance.
The handheld unit is light (11 Og) and small
(175 x 38mm), making it a natural addition to
a Network Maintained tool kit. The unit is
easy to operate with all tests performed by a
single press of a button. One 9V battery pow¬
ers the product and an RJ-45 coupler is
included for connecting to a patch cable.
For more information circle 162 on the
reader service card or contact Jamsam Pty
Ltd, Suite 202 James Hardie House, 65-69
York Street, Sydney 2000.
Aussie microPLC
for OEM users
Just released in the all-Aussie SPLat range of
microcontrollers is a model designed specifi¬
cally for OEM users. The easily programmed
and operated microPLC offers manufacturers a
cost effective alternative to fully custom-built
controllers and saves on engineering costs.
The MMI88 is based on a general purpose
SPLat controller — for timing, counting,
sequencing and digital control functions. It
features an inbuilt operator interface that is
specially tailored, with a polyester graphics
overlay, for the ‘look and feel’ needed in the
end application.
Designed by Microconsultants in Victoria,
the MMI88 is designed for machinery man¬
ufactured in small to medium volumes. The
system shortens the time needed to develop a
product and get it into the market place.
With a combination of eight inputs, eight
outputs, eight timers and a high speed
counter, plus five pushbutton switches,
seven LEDs, a beeper and two configuation
jumpers, the MMI88 performs simple to
2
| Ready
• Over Temp
* Cycle Done
"check 0«
f Sensor Fell
(§ Bin Empty
^ MMI88 @
Sample graphical CT)
overlay
@
Your graphics for >v>*r Q
product!
SPLtf «"****
complex control functions.
Microconsultants’ OEM support team also
offers a programming service to get manu¬
facturers going even faster.
For more information circle 163 on the
reader service card or contact
Microconsultants, 2/12 Peninsula
Boulevard, Seaford 3198.
Recordable DVD-R
and DVD-RAM media
TDK has announced DVD-R and DVD-
RAM recordable and re-recordable discs.
Although not available in Australian yet,
TDK (Australia) will meet market require¬
ments as they develop.
Offering storage capacity up to 5.2GB
(DVD-RAM double sided), the media
employ the latest in optical storage develop¬
ment technology. Compatible with current
DVD-R recordable drives, TDK’s DVD-R
uses a metal stablised cyanine dye as the
recording layer and gold as the highly reflec¬
tive layer. These integral layers are bound
together by a proprietary UV curing resin
bonding process that also aids in protecting
the disc.
TDK’s DVD-RAMs are a rewritable DVD
media offering storage capacity of 2.6GB
(single sided) and 5.2GB (double sided).
Designed to be re-writable for up to 50,000
times, the discs employ a Ge amorphous
alloy in the phase change layers (recording
layers) and aluminium for the reflective lay¬
ers. The four-layer construction is secured in
place by a proprietary UV curing resin bond¬
ing process.
For more information circle 164 on the
reader service card or contact TDK
Australia, 22 Lambs Road, Artarmon 2064.
Q International
FREQUENCY
CONTROL
PRODUCTS
CRYSTALS
FILTERS
OSCILLATORS
•QUARTZ
• CERAMIC
Hy-Q manufacture
and stock an extensive
range of Quartz
Crystals, Filters and
Oscillators including
TCXO and VCXO.
We also supply a full
range of high quality Ceramic devices at competitive
prices. Hy-Q specialises in quality, service and delivery.
Telephone (03) 9562 8222
Facsimile (03) 9562 9009
E-mail: hyq_aust@compuserve.com
BRIDGE THE GAP IN YOUR
POWER SUPPLY DESIGN
EDI UPl-series 60 amp bridges
assure the reliability of your
equipment with these features:
1000 amp surge handling capacity
Reverse voltages from 50 to 1000 volts
Available in fast recovery versions
Rapid assembly, through-hole mounting
Choose quick connect or wire leads
Don't delay, call or fax today for more
details and for catalogues on three-
phase bridges, hv diodes and assemblies.
Unit 2, 6-10 Maria Street Laverton North, Vic 3026
Tel: (03) 9369 8802 Fax: (03) 9369 8006
ELECTRONICS Australia, September 1998
95
READER INFO NO.33
Computer
News & New Products
Dual platform A3
Bubble Jet printer
Canon has released the new BJC-4650,
claimed as the industry’s first A3 Bubble Jet
printer for PC or Mac to offer users full
colour scanning (optional) and PhotoRealism
printing capabilities from a desktop printer.
The BJC-4650 is the only printer in its
class that is easily converted from a printer
into a colour scanner. The optional scanner
cartridge is substituted for the ink cartridge,
turning the printer into a colour scanner
capable of scanning resolutions up to
360dpi. This facility can be used to scan
images up to A3 in size, into a Windows 95
compatible computer.
The BJC-4650 also achieves near silver
halide photographic output using Canon’s
unique PhotoRealism and Drop
Modulation Technology.
By replacing the colour cartridge with the
black ink cartridge, the BJC-4650 produces
high speed, sharp, true black text documents.
Users can accomplish speeds of up to 4.5 A4
pages per minute in high-speed mode, and
with the text smoothing function documents
are near laser quality.
The BJC-4650 has an RRP of $599 and
comes complete with a four-colour ink car¬
tridge, a photo ink cartridge, five sheets of
glossy photo paper and a cartridge storage
container. Also available is the optional
scanner cartridge priced at $149 and a black
ink cartridge for $58.
For more information circle 165 on the read¬
er service card or contact Canon Australia, 1
Thomas Holt Drive, North Ryde 2113.
Keyboard and mouse adaptor
PI Engineering’s Keyboard and Mouse
Adapter is an active device that allows the
simultaneous use of both a full-size keyboard
and normal mouse on a notebook computer.
The adapter works with all notebooks that
feature a PS/2 keyboard/mouse port. It
requires no external power supply, drawing
power directly from the notebook port. Driver
software is included for Windows 95 and
Windows 98. No additional IRQ’s or com
ports are required.
Suggested retail price is A$129 including
tax, with a 12-month warranty.
For more information circle 167 on the
reader service card or contact BJE Enterprises,
124 Rowe Street, Eastwood 2122.
Rugged multi-axis joystick
Developed for use in those applications
where lever strength and handle functionali¬
ty are paramount — like virtual reality sys¬
tems — the Penny & Giles JC600 is a large,
robust, multi-axis joystick that can be easily
tailored to your application.
Designed for use with electronic controllers,
conductive plastic tracks inside the JC600
generate analog and switched reference sig¬
nals proportional to the distance and direction
over which the handle is moved. A centre tap
on the analog track provides an accurate volt¬
age reference for the centre position or a zero
point for a bipolar supply voltage.
The JC600 range of ergonomic handles fea¬
ture potentiometers, for three and four axes of
control, switches, membrane keypads or LED
displays. Deadman switches or a centre lock
option can be specified to improve the integri¬
ty of a control system. Installation time has
been reduced through the use of standard
electronic connectors. System cost can be fur¬
ther reduced by replacing the JC600 interface
board with a CANBUS or PWM controller.
With an expected life in excess of five
million cycles and designed to meet a lkV
voltage test, the JC600 is currently specified
by manufacturers of access platforms, agri¬
cultural, construction, mining and material
handling equipment.
For more information circle 168 on the
reader service card or contact Control
Devices Australia, Level 1, 150 William
Street, East Sydney 2011. ♦>
Pentium II based
Little Board SBC
Aaeon Technology has released the PCM-7890
Pentium II Little Board single board computer,
with on-board CRT/LCD controller and the new
DiskOnChip Flash Disk. The on-board 100BaseTX
Fast Ethernet interface, TV output and Sound
Blaster compatible audio opens up worlds of pos¬
sible applications for kiosks, gaming systems, POS
systems, medical and educational products.
The ultra compact board packs all the functions of an embedded PC on a single board, but fits
in the space of a 5-1/4” floppy drive. The on-board C&T 69000 is a high performance LCD/CRT
Windows accelerator incorporated with 2MB SDRAM for graphics/video frame buffer. It sup¬
ports a wide range of flat panel displays, including 36-bit TFT LCD displays allowing simultar
neous viewing of LCD/CRT and TV display.
The built-in DiskOnChip supports system boot-up and memory storage up to 72MB. The
fast Ethernet provides a tenfold increase in network capability; it is fully compatible with
lOMb/s network facilities. High quality sound requirements are also provided for, with an on¬
board PCI bus ES 1371 sound controller which is compatible with Sound Blaster, Sound
Blaster Pro and Windows Sound System.
Also included are four high speed serial ports (three RS-232, one RS-232/422/485), one
multi-mode (ECP/EPP/SPP) parallel port, a floppy drive controller, an Ultra DMA/33
enhanced IDE controller and a keyboard/PS/2 mouse interface.
For more information circle 166 on the reader service card or contact Amtex Electronics, 2 A
Angas Street, Meadowbank 2114.
96
ELECTRONICS Australia, September 1998
by Graham Cattley
B uilding your own pc really
isn’t that difficult you know, especial¬
ly after looking through Jeff Moe’s site
at http://www.verinet.com/pc/. He takes
you step by step through deciding what you
want, buying the bits, putting it all together
and so on. Just about all the pages warn you
that “...the info on this site is really old”,
but it covers 686’s at 150MHz, so it isn’t
that out of date. Besides, most of the info
here is relevant, no matter what speed CPU
you’re running.
He also has lots of useful links, and a sep¬
arate updates page for submitted material that
hasn’t had time to intergrate into the site.
Work left to do on these pages
Reviews..
Mfcrnai Dffcbiffc* £*<«*« m im
J£i' ——
All up, a useful, informative site that will
appeal to anyone contemplating building a
computer from scratch, or simply upgrading.
THE ELECTRONICS PLUS web site at
http://home.maine.rr.com/randylinscott/
covers a fair amount of ground, with sections
on the operation of faxes and photocopiers
(both of which are very good), cable
descrambling, and several simple projects to
build. It’s worth a look.
DOES YOUR COMPUTER have LRF sup¬
port? Do you know what LZW stands for?
and should DR.BOND be using FOSSIL on
the LAWN? Don’t know what I’m talking
about? Go to http://www.access.digex.net
/-ikind/babel.html, where Irving Kind main¬
tains the biggest acronym and abbreviation
index that I’ve ever seen. It comes as a huge
single page, so you’ll have to wait for all of it
to load in before you start searching — or you
can FTP the zipped text version from
ftp.access.digex.net. Irving updates it three
times a year, and so the whole thing is quite
compehensive and up to date. (Although I
couldn’t find LRF, which stands for Little
Rubber Feet...)
THE NANO ART GALLERY at
http://www.hitachi.co.jp/Div/keisokuki/en
glish/nano/arte.html is very good —
Cherry Blossoms in a Clear Stream is quite
beautiful, as are the Gold Moon and Desert
Passion photos. They’re photomicrographs
of course, but taken out of context and suit¬
ably coloured they take on a whole new
meaning. It’s all very Japanese, and well
worth the effort of typing in the long URL.
CONSIDER THIS the next time you are
online: one white pixel uses up 34,475,867,928
electrons per second. An average 14” screen
uses 18,237,881,012,857,875,948,329,134,987
electrons per second. These electrons are
destroyed and cannot be used again. See
what’s being done to save the electron at
http ://www.and rew.cm u.edu/~j j s 2
/electrn.html
CAR AUDIO is always a hot subject, and
the mobileaudio.com site (at
http://www.mobileaudio.com/, of course)
can give you heaps of stuff on the subject,
mainly via their rec.audio.car FAQ (yes,
from the Usenet newsgroup).
Their White Pages list the sites of people
around the world where you can see other
installations and even email other car audio
enthusiasts. There are details of upcoming
‘sound-off competitions (mostly in the US),
a colourful report of the new car audio prod¬
ucts at the recent ICES, and links to car
audio retailers online. So if you see your car
as merely a speaker box on wheels, this site
should be of great interest.
IF YOU ARE HAVING TROUBLE with
your VCR, then why not pay a visit to
http://bradley.bradley.edu/~fil/vcr.html,
where Philip Kuhn offers a listing of Q&As
on just about every aspect of owning and
operating a VCR. An interesting image
map indexing system takes you quickly and
easily to the relevant section, with useful
hints and tips on the section of VCR that
you clicked on.
And if you are still one of the many suf¬
fering from a blinking 12:00 on your VCR,
check out http://www.soundsite.com/vcr
/vcr.html, which covers the time setting
procedures for a multitude of popular
domestic VCRs. ❖
ELECTRONICS Australia, September 1998
97
EA Directory of Suppliers
Which of our many advertisers are most likely to be able to sell you that special component, instrument,
kit or tool? It’s not always easy to decide, because they can’t advertise all of their product lines each
month. Also, some are wholesalers and don’t sell to the public. The table below is published as a spe¬
cial service to EA readers, as a guide to the main products sold by our retail advertisers. For address
information see the advertisements in this or other recent issues.
Supplier
State A
B
C
D E
F
G
Altronics
WA
•
•
• •
•
•
Dick Smith Electronics
ALL
•
•
• •
•
•
Emona Instruments
NSW
•
Jaycar Electronics
Eastern •
•
•
• •
•
•
Oatley Electronics
Eastern •
• •
Obiat
NSW
•
RCS Radio
NSW
•
Scientific Devices
VIC
•
KEY TO CODING
D
Components
A Kits and modules
E
1C chips and semiconductors
B Tools
F
Test and measuring instruments
C PC boards and supplies
G
Reference books
Note that the above list is based on our understanding of the products sold by the firms concerned.
If there
are any errors or omissions, please let us know.
Electronics Australia Reader Services
SUBSCRIPTIONS: All subscription enquiries should be directed to: Subscriptions Department, Federal
Publishing Company, P.0. Box 199, Alexandria 2015; phone (02) 9353 9992.
BACK ISSUES: Available only until stocks are exhausted. Price A$7.50 which includes postage within
Australia only. OVERSEAS READERS SHOULD ADD A FURTHER A$2.50 FOR EVERY BACK ISSUE
REQUIRED.
PHOTOCOPIES: When back issues are exhausted, photocopies of articles can be supplied. Price $7.50 per
project or $15 where a project spreads over several issues.
PCB PATTERNS: High contrast, actual size transparencies for PCBs and front panels are available. Price is
$5 for boards up to lOOsq.cm, $10 for larger boards. Please specify negatives or positives.
PROJECT QUERIES: Advice on projects is limited to postal correspondence only and to projects less
than five years old. Price $7.50. Please note that we cannot undertake special research or advise on pro¬
ject modifications. Members of our technical staff are not available to discuss technical prob¬
lems by telephone.
OTHER QUERIES: Technical queries outside the scope of ‘Replies by Post’, or submitted without fee, may
be answered in the Information Centre’ pages at the discretion of the Editor.
READER SERVICES BULLETIN BOARD: (02) 9353 0627; ANSI, 24 hour access; any rate to 28.8kb/s.
PAYMENT: Must be negotiable in Australia and payable to Electronics Australia. Send cheque, money order
or credit card number (American Express, Bankcard, Mastercard or Visa card), name and address (see form).
ADDRESS: Send all correspondence to: Reader Services Co-Ordinator, Electronics Australia, P.O. Box 199,
Alexandria NSW 2015; phone (02) 9353 0620. (E-mail to ea_readerservice@hannan.com.au)
PLEASE NOTE THAT WE ARE UNABLE TO SUPPLY BACK ISSUES, PHOTOCOPIES OR PCB ARTWORK
OVER THE COUNTER.
Name;.
Address:..
.State:.Postcode:
Back issues:
Photocopies:
Amount: A$.
Signature:.(Unsigned orders cannot be accepted.)
Method of Payment: (Please circle correct method.) Credit card / Cheque / Money order.
Credit cards accepted:
Mastercard, American Express, Visa Bankcard (please circle applicable card).
Expiry date:.
ADVERTISING INDEX
Allthings Sales & Services.43
Altronics .64-66
Bainbridge Marine.33
Bendigo College of TAFE.9
Campad Electronics .83
Central Park Electronics .83
Computronics.83
Control Devices.85
DaviCAD.83
Dick Smith Electronics .38-41,IFC.OBC
EA subscriptions offer.82
Elenex .60
Evatco .71
Fastron Australia.33
Griffith University .9
Harbuch Electronics .81
Hewlett-Packard Australia.13
Hy-Q International.95
Instant PCBs.83
Jands Electronics .73
Jaycar Electronics .52-55
JED Microprocessors .51
McLean Automation .81
Microgram Computers .23
Netcraft .63
Oatley Electronics .IBC
Obiat .87
Procon Technology.61
Result Electronics.35
Questronix .22
Scan Audio.22
STA .81
Taig Machinery.83
Tandy Electronics.29
VAF Research.12
Valve Electronics.73
Westek Industrial Products.95
This index is provided as an additional service. The
publisher does not assume any liability for errors or
omissions.
Notes & Errata
Forum column (July 1998): The telephone num¬
ber given for Melbourne firm Bio Electronics is
wrong; it should be (03) 9370 6729.
240V Variable Frequency Drive (July 1998): In
the schematic diagram on page 57, rectifier bridge
B1 should be rotated clockwise by 90°; also zener
diode Z2 is reversed. The PCB overlay is correct.
Motorcycle Intercom (July 1998): Capacitor C2
should be a lOuF electrolytic, not luF as shown in
the schematic. The parts list and overlay diagram
are correct.
$10 Wonders (June 1998): In the stripboard over¬
lay on page 67, the LED anode should connect to
J6, to connect to R3. Also the flying lead should
connect to track H11, not F12 as shown. Thanks to
Ted Kilminster for advising of these errors. ♦>
98
ELECTRONICS Australia, September 1998
LASER DIODE POINTER ( Key-chain )
Very bright ( 650 nM ) pointer, supplied
with 4 extra lens caps that
produce symbols; CUPID
I LOVE YOU, LOVE
HEARTS&A
LADY. $29
LASER DIODE MODULE
Same quality module that
is used in the above
laser pointer: $24
NEW POCKET SAMPLER KIT FOR PC’S
THAT FITS INTO A Db25 HOUSING.
Data logger/sampler plugs into your Pc’s
parallel /printer port & takes samples over
a 0-2V or 0-20V range. Samples can be
taken at intervals from one per hour down
to one per IOOuS. Useful, for example, to
monitor battery charging. It can also be
used as a basic low frequency (to about
5KHz) oscilloscope! Our kit includes all
onboard components, A _
PCB, Db25 $40
housing
&the
software on
a 3.5" disk:
(K90)$25
PC Data Acquisition Unit
Use the parallel port of your PC as a real
world interface. It enables your PC to both
monitor & control external events and
devices. The world is a mixed analog &
digital world. VMth the appropriate sensors
the PC can monitor physical variables
such as pressure, temperature, light
intensity, weight, switch state, movement,
relays, etc, process the information and
then use the result to control physical
devices such as motors, sirens, other
relays, servo motors (up to 11) & two
stepper motors :$200
KITS OF THE MONTH
12VDC - 240AC INVERTER Features include modified square wave output, Auto
start with load sensing, Uses six power MOSFETS
with minimal heatsinking required. 200-
600VA. dependant on transformer size.
To save money you can use an rewind
your own transformer. Basic kit includes
pcb & all on-board components + 4 60A
MOSFETS. $35 Requires 240V to 8-0-8 V
transformer. Low profile case + Australian
made300VA. (cont.) trans-former for approx. $100.
20-30 SECOND SOUND/VOICE RECORDER KIT.
This kit could be used as an answering machine at your front door or as a personal
reminder device and is very easy to assemble
Produces very good quality sound at 25
sec (better than most expensive units),
Uses Large Scale Integration
chip with memory etc. all
built in. Kit includes
PCB, all on-board
components, electret
microphone, switches &
small surplus speaker. $ 19
FREE ADS ON OUR WEB SITE FOR
COMPANIES & INDIVIDUALS
CONDITIONS APPLY
DON’T MISS THE BARGAINS NOT SHOWN IN THIS AD
ON OUR BARGAIN CORNER PAGES ( UPDATED
REGULARY ) OVER 25,000 HITS PER WEEK.!!!
www.ozemail.com.au/~oatley
soon to be (oatleyelectronics.com)
""♦"CLEARANCE SPECIAL""
UHF AUDIO-VIDEO TRANSMITTER.
Your own mini Tv broadcast static
Send video from VCR's or $i5
cameras to TVs in your ^
home. Inc. Metal case
telescopic antenna & leads:
12V operation, tunable (G01)
$20 or $15 with camera purchase
We HAVE NEW STOCKS OF STEPPER
MOTORS 30 oz./in. TORQUE, 2.5 DEG.
(144 STEP), LOW VOLTAGE, COMPACT
57X38MM
♦ TWO GREAT SPECIALS ""
STEPPER MOTOR DRIVER KITS*"
COMPUTER CONTROLLED STEPPER
MOTOR KIT: can drive larger motors with
optoisolation. Inc. software and notes: $50
or $65 with two used 2.5 deg.jriotorsji
STEPPER MOTOR
DRIVER KIT Kit inc. a large
used 2.5 deg. (144 step/
rev) motor & uses SAA-
1042A 1C. Controls inc. ext. clock,
on-board clock logic CWor CCWrotation,
half or full step, enable/disable, clock
speedl motor: $25 or 2 motors:$35
FM TRANSMITTER 33 x 23 xJOmm
In a small black metal
case. Built in switch &
microphone. Specs.:
88 to 108-MHz (adj.),
with a wire ant. bat. life 60^
hrs, Range 50M:(G14) $39
(Std. watch battery LR44, inc.)
FRONT SURFACED MIRRORS
High quality mirrors 160x22x2.5mm.
with some minor blemishes Ideal for laser
& other optical projects $5
HIGH RESOLUTION MONITOR
Brand new 240V
30cm enclosed
computer monitor
+ video conversion
kit. Gives better
resolution than TV!
Limited good qty.
BARGAIN PRICE.
MODEL TRAIN CONTROLLER KIT:
Ref: SC Jul 95. Allows two trains to run on
one track, without hitting each other due
to speed difference. VMien a train breaks
an IR beam it switches off power to a
portion of track, until the other train
catches up & breaks another beam at
another location. It uses a relay to switch
sections of track. Main PCB: 96 x 66mm,
IR Sensing PCB's: 59 x 14mm: (K58) $28
AUTOMATIC LASER LIGHT SHOW KIT:
MKIII. Similar kit as per SC. May 96, The
display changes every 5 - 60 secs, & is
manually adjustable. For each displays
there are 8 speeds for each of 3 motors,
one motors can be reversed in direction, &
one motors can stopped. There’s
countless interesting displays which vary
from single to multiple flowers, collapsing
circles, rotating single and multiple
ellipses, stars, etc. Now with no more
mirror and motor alignment hassleswith
motor mounting on the PCB and mirrors
now align with “Allen Key”. Kit includes
PCB, all on board components, three
small DC motors, mirrors, precision
adjustable mirror mounts :(K83)
SOLID STATE 4-6A PELTIER EFFECT
COOLER /HEATER
3.3 A@ 14V PELTIER: $27, 6A
@15VPeltier: $35, both are approx.
40X40X4mm, can be temperature con¬
trolled by reducing supply voltage
/current, will even work from a 1.5V
battery!! V\te supply Peltier Effect device,
data sheet, diagram & circuit for a small
fridge / heater.. Other requirements; In¬
sulated box, 2 large heatsinks, & a small
aluminium block, this device is used in the
common 15Lrcar
fridge. Peltier effect
Device:(G02) 12 V,
DC Fan:(G11)
OATLEY ELECTRONICS
PO Box 89 Oatlev NSW 2223
Ph (02) 9584 3563 Fax 9584 3561
orders by e-mail: oatley@world.net
http://www.ozemail.com.au/~oatley
major cards with ph. & fax orders,
Post & Pack typically $6
TRANSISTOR SPECIALS
BU-205
HIGH VOLTAGE
$2.50
2SD-1554
HIGH VOLTAGE
$5.00
"SPECIAL"SPECIAL"SPECIAL"
FOR $1 EXTRA WITH EACH ORDER
WE WILL SEND A WIRING KIT !!!
Great for cars, radios mobile phones, fog
lights etc. 4 colours, 2 guages of wire,
Spade connectors, fuse holders, fuses.
17+ mtrs. of wire. Limited offer! 11 just $1
"* SPECIAL BARGAIN "*
12V/7Ah GEL BATTERY BARGAIN
Fresh stock of NEWstandard battery $22
NEW I 4Ch. UHF
LEARNING REMOTE %
Can be programmed as
a spare for your current
remote or to replace up
to 4 other units and
combine into 1:(TX1) $39
UHF DATA TRANSMISSION
Stamp sized Xtal locked 433.9MHz
superhetrodyne receiver module $25
Small matching transmitter kit: $12
00 *-
m
CD
0|» o D
PRO. STUDIO QUALITY REVERB
Three spring units. Dim.: 425 x 110 x
33mm. Input Z=190 ohms, output Z=2.6
k ohms, recommended AC drivej,
6.5 mA. A circuit diagram
of a stereo pre¬
amp tested
using this a o
unit:$40(A10) s>4U
CCD CAMERA SPECIAL
The best "value for money" CCD camera
on the market! 0.1 lux, High IR response &
high res. Performs better thgn_ many
cheaper models. WITH
CHOICE OF 1 OF
THESE LENS
Pinhole (60deg.),
;78deg.; 92 deg.;
120 deg.; $89 or 150 deg: $99
HIGH QUALITY DC MOTORS
3V - 8v DC motors with feedback winding
for speed sensing ect. 40mm diameter
X35mmlong$3
*" HALF PRICE SUPER SPECIAL
Lm338 adjustable ( T03 package ) 5A
voltage regulator with int ernal ov erload
protection, + applicatioj
notes for a variable
1.2V- 33V 5-20A
power supply
Half price at
just$6Ea
or 4 for $16
RESELLERS PRICES FOR
MANY OF OUR & STOCK
ITEMS AVAILABLE SOON TO
INTERESTED BUSINESSES
E-MAIL US YOUR BUSINESS DETAILS
"* NEW *" NEW *" NEW "*
HIGH POWER IR TRANSMITTER AND
RECEIVER Applications include data
transmitter, powerful Passive infrared de¬
tector, IR invisible fence / gate & doorway
monitor. Range: with 5 IR LEDs (can drive
up to 50 LEDs) passive mode 10m (5
LEDs), active mode 40m (5 LEDs). Range
can be boosted with a cheap torch re¬
flector. The kit has active high & active low
outputs for relays etc Simple to construct
PCB can be cut into two for active mode or
for data transmission. Kit inc. PCB, all on¬
board components, 5 IR LEDs + salvaged
new plastic case All for $28
TELLEFUNKEN DUAL GaAs-MES-FET
Cf300, LOWNOISE (NF=1.4 @800 Mhz)
V\fould make extremely low
noise RF amp (Gps 23db).
WAth brief info. $3 Ea or 5 for $13
$2 " YES " $2
VHF VIDEO 1-2 MINI MOD¬
ULATORS WITH EVERY,
CAMERA YOU BUY
OR HAVE BOUGHT IN
THE PAST. INC DATA
SHEET:$ 2 (Rm2). This unit [fit neatly
with our camera in our 50; J ^
50x50mm case + swivel
mount strong adjustable
universal bracket: $4
Bracket only :$ 1.50
FANTASTIC BARGAIN "*
COMPUTER POWER SUPPLY PCB:
New assembly. 45 x 108 x 200mm. 120 /
230V AC input. DC outputs are +5V@
6A.+ 12V@ 1A,-12V@1A,-5V@1AJ3ata
Inc.RU approval. Mail
input. Be Quick:
(Ps6)$12ea.
or 4 for $36
IR RECEIVER FRONT END MODULE
This device contains an IR
receiver diode, an amplifier
tuned to 38KHz, a bandpass
filter, an AGC section & de¬
tector circuit. $2 Ea or 10 for $15
PLASMA DISPLAY BALL KIT:
High Power High Frequency
EHT generator that will give an
exciting plasma discharge with
a std light bulb or make Jacobs
Ladder or Laden Jar & other EHT
applications. Can be converted to
a DC. Supply with a HV diode.
Inc. EHT transformer + PCB
all on-board parts & 1KV. fast
Diode + application notes. Req
12V @ 0.5-2A. Special price $29.
16KV. Diode $1.50
BRAND NEW STD LC DDISPLAYS
lline x 16char.:$16 p
2 line x 16 char, with
LED back-light:$24
NEW HITACHI LASER DIODES,
40mW/785nM For scientific,
medical and industrial
applications: $65
35 mW/650 nM: $90
*" SPECIAL
BRAKE LIGHT INDICATOR-60 LED KIT
This kit has two PCB's + current limit
resistors + 60 LED's to make a very bright
brake light etc. 600mm long: $15
HIGH
—-’♦CLEARANCE SPECIAL’
FLUORESCENT LIGHT
FREQUENCY BALLASTS
European made, new, "slim line" case high
frequency (HF) electronic ballasts. Flicker
free starting, long tube life, high efficiency,
visual flicker during operation. Reduced
radio frequency interference. Similar
design to one published in the Oct. 94
Silicon Chip, although these are much
more complex. Dimming requires external
100K pot or a 0-10V DC source. V^eJiave a
limited stock 1 x 36W
tube, 28 x 4 x
3 cm: (G09F)
iust $18
Reader Info No 34
Credit card remote
One instead of four!
Integrates up to four different controls into one
ultra-slim credit card size remote.
Pre-programmed and easy
to use.
digitor
G 1220
37 95
Universal remote control
jog shuttle
Replace up to 8 remotes with this easy-to-use
master controller. Pre-programmed and learning.
LCD screen,Teletext function and
jog/shuttle control. G 1212
FOX600 Universal remote control
Control six devices from one remote! This easy-to-use
pre-programmed unit is ideal for TVs, VCRs, satellite
receivers, cable boxes and CD players.
Includes teletext, g 1225
digitor
69
Commander remote control
Reduce remote clutter with this 8-in-1,full LCD
touch screen remote with macro functions. Home
theatre/surround sound ready.
G 1210
digitor
Help is Just A Toll-Free Phone Call Away!
The most user-friendly Universal Remote Controls Available. If you ever have any questions or need
help of any kind to program your One for All Remote Control, Just call 1-800-064-472 (Toll-free)
I for 3 universal remote control
Great new design!
Throw out your old remote controls! This
pre-programmed unit replaces up to 3
remotes. Now access
Jp J|dL|| y° urTV ’ VCR and cable
from the one remote.
G 1271
I for 4 universal remote control
Backlit, and replaces up to 4 remotes.
Pre-programmed for TVs,VCRs,
cable boxes and CD players.
G 1261
79
PHONE FAX &
MAIL ORDERS
direct; Jink
PICK^SMITH
ELECTRONICS
PHONE: 1300 366 644 (Local Call Charge) FAX: (02) 9395 1155
MAIL: DICK SMITH ELECTRONICS, Direct Link Reply Paid 160.
PO Box 321. North Ryde NSW 21 13 (No Sump Required)
Please add postage (up to Skg) to your order, as follows:
• $4.00 Up To $50 • $7.50 $51 Up To $100 • $9.00 $101 Up To $500 • $11.00 over $500
(quote available for air/road freight or if over 5kg) email: dse.directlink@bigpond.com (enquiries only)
•Major Credit Cards Accepted. • Gift Vouchers Available
I for 5 universal remote control
Easy-to-use and conveniently
replaces up to 5 remotes
including TVs, VCRs, cable
boxes, CD players,
audio equipment. g 1250
I for 6 universal remote control
Pre-programmed and easy set up. Controls TVs,VCRs,
cable boxes, audio appliances
and Teletext. Replaces up
to 6 remotes. G 1240
Universal remote control
A/V producer I for 8
Access up to 8 devices from one remote!
Pre-programmed unit includes backlit keypad,
LCD and home theatre mode
169
G 1280
For further information, orders or the
location of your nearest store call:
1300 366 644 (Local Call Charge)
Or Fax: (02) 9395 1155
B3443 OBC
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